Liquid crystal display device

ABSTRACT

A timepiece provided with a liquid crystal display panel ( 9 ) for displaying thereon at least one of time information ( 5 ) and calendar information ( 4 ), wherein a solar battery unit ( 12 ) is provided to face at least a part of a visual recognition side surface of the liquid crystal display panel ( 9 ) or an opposite-side (lower-side) surface thereof, the light being applied to a power generation portion of the solar battery unit ( 12 ) through a transmission portion of the liquid crystal display panel ( 9 ) to generate electric power or what is displayed on the liquid crystal display panel ( 9 ) being visually recognized through a transmission portion of the solar battery unit ( 12 ), a timepiece circuit and the liquid crystal display panel ( 9 ) being driven by utilizing the electric power generated by the solar battery unit ( 12 ).

TECHNICAL FIELD

The present invention relates to a timepiece provided with a liquidcrystal display panel for displaying at least one of time informationand calendar information.

BACKGROUND TECHNOLOGY

In a timepiece for digitally displaying time information and calendarinformation, or in a combination timepiece made by combining the digitaldisplay of them and an analog display using hands, a liquid crystaldisplay panel is used to perform the digital display.

In such a conventional timepiece using the liquid crystal display panel,a battery of simple consumption-type or charging-type is typically usedas an energy source (electric power source), and additionally there isone type in which a solar battery is provided around the liquid crystaldisplay panel, and electric power generated by it is accumulated in asecondary battery to use.

When the earth's environmental problems and energy problems are focusedon, the simple consumption-type battery will have a serious problem inwaste-disposal in the future, or the charging-type battery will have anenergy consumption problem if it is charged through supply of electricpower from an external power source.

Further, replacement of batteries is not preferable, especially for atimepiece, in maintaining a good waterproof state and in the preventionof the introduction of dust into its case. Further, a timepiece has lowpower consumption, and thus its timepiece system can be driven withlittle quantity of power generation. Therefore, it is preferable toinstall a solar battery in the timepiece to supply the entire or atleast a part of the consumed electric power by power generation of thesolar battery, thereby offering a great expectation of no waste producedand self-sufficient energy in the future.

In the timepiece using the conventional solar battery as the energysource, however, the solar battery is too conspicuous, and additionallyit is necessary to secure a relatively large area for the solar battery,causing great restriction in visual design.

An example of a timepiece using a conventional solar battery as anenergy source is explained here with reference to the drawings.

FIG. 35 is a schematic plan view showing an example of a conventionaldigital wristwatch with solar batteries. FIG. 36 is a schematiccross-sectional view taken along a line XXXVI—XXXVI in FIG. 35.

In this wristwatch, as shown in FIG. 35, a liquid crystal display panel9 is disposed at the center of the upper surface of a watch case 1, anda number of solar batteries 15 are arranged in rows on both sides of theliquid crystal display panel 9.

The liquid crystal display panel 9 is provided with a chronographdisplay portion 3, a year-month-date display portion 4 and a timedisplay portion 5. Further, four mode adjusting buttons 10 forcorrecting display contents, adjusting time and the like are provided onthe side face of the watch case 1.

The watch case 1 seals the inner space with a cover glass 2 and a caseback 7 as shown in FIG. 36.

In the watch case 1, the liquid crystal display panel 9 and fours solarbatteries 15 provided on either side thereof are arranged inside thecover glass 2. A circuit board 6 is disposed below them, which includesa timepiece circuit operating by being supplied with electric power fromthe solar batteries 15, a drive circuit for driving the liquid crystaldisplay panel 9, and the like.

Around the solar batteries 15 and the liquid crystal display panel 9, apanel cover 25 is provided, which shields electrodes and their outerforms.

In the liquid crystal display panel 9, a first substrate 21 and a secondsubstrate 22, each of which is made of transparent glass or the like,are bonded together opposed each other with a predetermined gapinterposed therebetween with spacers (not shown) and a sealing portion23, and a liquid crystal layer 14 is sealed in the gap.

The opposed inner faces of the first substrate 21 and the secondsubstrate 22 are provided with signal electrodes, opposed electrodesopposed to the signal electrodes to form pixel portions, and alignmentfilms, though their illustration is omitted. A twisted nematic (TN)liquid crystal with a twist angle of 90 degrees is used for the liquidcrystal layer 14.

In order to allow a change in alignment state of liquid crystalmolecules caused by voltage applied to the liquid crystal layer 14 usedin the liquid crystal display panel 9 to be viewed, a first polarizingfilm 16 and a second polarizing film 17 are bonded to the upper side ofthe first substrate 21 and the lower side of the second substrate 22respectively with an acrylic resin. Each of the first and secondpolarizing films is an absorption-type polarizing film of which onepolarizing optical axis is a transmission axis and a polarizing opticalaxis perpendicular thereto is an absorption axis, and the firstpolarizing film 16 and the second polarizing film 17 are arranged sothat the respective transmission axes are perpendicular to each other.

This brings a portion where voltage is not applied between the signalelectrode and the opposed electrode of the liquid crystal display panel9 into a light transmission state, and a portion where voltage isapplied into a light absorption state, thereby presenting a display.

Further, a translucent-type reflector 18 made by evaporating aluminum(Al) film to a transparent resin film is bonded to the lower side of thesecond polarizing film 17, and, opposed to that, an auxiliary lightsource 19 composed of an electro-luminescent (EL) element is provided onthe circuit board 6.

When an external light source is dark, that is, when the environment ofthe watch in use is dark, the auxiliary light source 19 is turned on.Emitted light from the auxiliary light source 19 is made incident on theliquid crystal display panel 9 through use of transmissioncharacteristics of the translucent-type reflector 18, presenting atransmission-type display.

When the external light source is bright, use of reflectioncharacteristics of the translucent-type reflector 18 enables areflection-type display.

A secondary battery 8 for accumulating electric power generated by thesolar batteries 15 is provided on the back face side of the circuitboard 6. These constituted a timepiece module having a function ofgenerating electric power.

There also is a combination watch though the illustration thereof isomitted, which digitally displays lap time of a chronograph and a year,a month and a date by a liquid crystal display panel and includes anhour hand, a minute hand and further a second hand to analog-displaytime with the hands, in which solar batteries are annularly arranged atthe peripheral portion of a dial, and electric power generated by thesolar batteries is used as electric power for a liquid crystal displayand drive of the hands.

In either structure of the conventional timepieces (watches), the solarbatteries are viewed from the outside, which is not preferable in visualdesign. The liquid crystal display panel and the solar battery arelocated at different positions, making an outer form of the timepiecelarge as compared to the proportion of the display area of the liquidcrystal display panel. Further, there also is a problem that a largedisplay area of the liquid crystal display panel occupies a space wherethe solar battery is disposed.

DISCLOSURE OF THE INVENTION

The present invention is made in view of the above described technicalbackground, and an object of the present invention is to obtain afunction of generating electric power by a solar battery in an area of aliquid crystal display panel, to obtain a sufficient display area and asufficient quantity of power generation even if the present invention isapplied to a small-sized timepiece, to enable elimination of powersupply from the outside and battery exchange, and further to provide atimepiece excellent in visual design with an unobtrusive solar battery.

In order to attain the above-described object, the timepiece accordingto the present invention is a timepiece provided with a liquid crystaldisplay panel for displaying thereon at least one of time informationand calendar information, wherein a solar battery is provided to face atleast a part of a surface opposite to a visual recognition side of theliquid crystal display panel, and light is applied to the solar batterythrough a transmission portion of the liquid crystal display panel togenerate electric power.

A film with substantially the same spectral reflectance as that of apower generation portion of the solar battery is provided on the visualrecognition side of an electrode portion of the solar battery, allowingthe electrode portion and the power generation portion to be viewed inthe same color.

A film having substantially the same spectral reflectance as that of thepower generation portion of the solar battery may be provided around thesolar battery.

A film for changing a color of the solar battery may be provided betweenthe solar battery and the liquid crystal display panel.

It is possible to make a part of a display region of the liquid crystaldisplay panel a power generation quantity adjustment region for changinga transmittance to adjust a quantity of power generation of the solarbattery.

It is preferable to provide means for conducting a control to increase atransmittance of the liquid crystal display panel to increase a quantityof power generation of the solar battery while the liquid crystaldisplay panel is in a non-driving display state.

It is preferable to configure so that a display with low brightness bythe liquid crystal display panel is performed using a low reflectancecharacteristic of the solar battery.

It is also preferable to configure so that a display is performed by achange in color of the liquid crystal display panel and a spectralreflection characteristic of the solar battery or the film.

It is possible that a mixed liquid crystal layer made by mixing adichroic dye in a liquid crystal or a mixed liquid crystal layercontaining a polymer in a liquid crystal is used for a liquid crystallayer of the liquid crystal display panel.

Alternatively, it is preferable that the liquid crystal layer is atwisted nematic liquid crystal layer or a super twisted nematic liquidcrystal layer, polarizing films are provided on the visual recognitionside and on the opposite side thereto respectively with the liquidcrystal layer interposed therebetween, and the polarizing film providedon the opposite side to the visual recognition side is a reflection-typepolarizing film, a cholesteric liquid crystal film, or a ¼ λ plate and acholesteric liquid crystal polymer.

Further, it is preferable that the solar battery is formed in a unithaving a transmission region for transmitting light and a powergeneration region for absorbing light to generate electric power. It ispreferable that the power generation region is provided at a positionfacing a non-display region around a display pixel portion of the liquidcrystal display panel, and the transmission region is provided at aposition facing the pixel portion of the liquid crystal display panel.

It is also suitable that the power generation region of the solarbattery is provided at a position facing at least a panel cover portionaround a display region of the liquid crystal display panel, and thetransmission region is provided at a position facing an inside of thedisplay region of the liquid crystal display panel.

In these timepieces each using the solar battery unit having thetransmission region, it is possible that an auxiliary light source isprovided on a side of a surface opposite to a surface facing the liquidcrystal display panel of the solar battery unit to allow light to beapplied from the auxiliary light source through the transmission regionof the solar battery unit to the liquid crystal display panel.

A timepiece is also provided, in which, conversely to theabove-described timepiece, a solar battery unit is provided on a visualrecognition side of the liquid crystal display panel so that at least apart of the solar battery unit overlaps the liquid crystal displaypanel, and the solar battery unit has a transmission portion and a powergeneration portion so that a display by the liquid crystal display panelis performed through the transmission portion.

It is preferable that a printed layer for cover is provided at a part ofthe visual recognition side of the solar battery unit.

The liquid crystal display panel may be constituted of a mixed liquidcrystal layer composed of a liquid crystal and a transparent solidsubstance sealed in a gap between a first transparent substrate and asecond transparent substrate.

A reflector may be provided on the opposite side to the solar batteryunit with respect to the liquid crystal display panel. Further, it ispreferable that an auxiliary light source is provided on the firstsubstrate side (visual recognition side) of the liquid crystal displaypanel.

It is possible that an area ratio between the transmission portion andthe power generation portion of the solar battery unit is differentdepending on a place of the liquid crystal display panel which the solarbattery unit overlaps.

The solar battery unit may have a transparent substrate, and thetransparent substrate has a scattering property within a region wherethe transparent substrate overlaps a portion of the liquid crystaldisplay panel except for a display region.

It is preferable that a light guide portion for guiding light of anexternal light source to a display region of the liquid crystal displaypanel is provided at an outer peripheral portion of the solar batteryunit.

It is desirable that a ratio of an area of the transmission portion withrespect to a total area of the area of the transmission portion and anarea of the power generation portion of the solar battery unit is 30% ormore, and a width of the power generation portion is 100 micrometers(μm) or less.

It is desirable that light-shielding with respect to the liquid crystaldisplay panel by the power generation portion of the solar battery unitis 20% or less of pixel portions of the liquid crystal display panel.

It is preferable that the power generation portion and the transmissionportion are regularly arranged in stripes or in concentric circles.

It is possible that a circuit board connected to the solar battery unitand the auxiliary light source is provided, and a connection between thesolar battery unit and the circuit board and a connection between theauxiliary light source and the circuit board are established throughintegrated connecting media composed of the same material.

It is preferable that an ultraviolet cut layer for preventingdeterioration of the liquid crystal display panel is provided on thevisual recognition side of the solar battery unit.

It is preferable that a wavelength conversion layer for converting light(ultraviolet light) with a wavelength less than 400 nanometers (nm) tolight with a wavelength of 400 nanometers (nm) or greater is provided onthe visual recognition side of the solar battery unit. Further, it ismore preferable that an ultraviolet light cut layer for blocking thelight with a wavelength less than 400 nanometers (nm) is providedbetween the wavelength conversion layer and the solar battery unit.

At least a part of a substrate of the solar battery unit or a coverglass of the timepiece may be a wavelength conversion layer forconverting light with a wavelength less than 400 nanometers (nm) tolight with a wavelength of 400 nanometers (nm) or greater.

In these timepieces, when a hand for indicating time is provided, thesolar battery unit is provided with a through hole into which a shaft ofthe hand is inserted. Further, it is preferable that the solar batteryunit and the liquid crystal display panel are provided with throughholes into which a shaft of the hand is inserted at positions facingeach other within portions where they overlap one upon another.

It is desirable that a resin portion for preventing breakage is providedat least on an inner peripheral surface of the through hole of asubstrate of the solar battery unit.

In these timepieces, an auxiliary light source can be provided on theopposite side to the visual recognition side of the liquid crystaldisplay panel.

Further, a plurality of solar battery units using light with differentwavelengths at power generation portions thereof may be provided inlaminated layers.

A solar battery unit can also be provided on the opposite side to thevisual recognition side of the liquid crystal display panel in additionto the solar battery unit provided on the visual recognition side of theliquid crystal display panel.

Further, when the liquid crystal display panel has a liquid crystallayer coupled by a pair of transparent substrates and has a nonlinearresistance element on one of the substrates for switching a signal to apixel portion, it is possible that a power generation portion of a solarbattery is provided on the one substrate of the liquid crystal displaypanel, and semiconductor layers of the power generation portion and thenonlinear resistance element are formed of the same semiconductor.

The power generation portion of the solar battery can be provideddirectly on the one transparent substrate of the liquid crystal displaypanel.

At least the substrate on the solar battery side out of the pair ofsubstrates of the liquid crystal display panel can be made of an organicmaterial.

It is preferable that the power generation portion and the transmissionportion of the solar battery unit are regularly arranged in stripes, anda pitch between adjacent power generation portions of the solar batteryunit and a pitch between adjacent pixel portions of the liquid crystaldisplay panel are substantially the same.

It is suitable that the liquid crystal display panel becomes any one ofa scattering state, a transmission state and a reflection state when novoltage is applied thereto.

It is also possible that the power generation portion of the solarbattery unit has a structure of sandwiching a semiconductor layerbetween two electrodes, and either of the two electrodes is made of atransparent conductive film.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic plan view showing a first embodiment of atimepiece according to the present invention;

FIG. 2 is a schematic cross-sectional view taken along a line II—II inFIG. 1;

FIG. 3 is a schematic plan view of only a solar battery unit 12 in FIG.1 and FIG. 2;

FIG. 4 is a schematic plan view of only a liquid crystal display panel 9in FIG. 1 and FIG. 2;

FIG. 5 is a schematic cross-sectional view showing a first structuralexample of a liquid crystal display device taken along a line V—V inFIG. 4;

FIG. 6 is a schematic cross-sectional view showing a second structuralexample of the liquid crystal display device of the same;

FIG. 7 is a schematic cross-sectional view showing a third structuralexample of the liquid crystal display device of the same;

FIG. 8 is a schematic plan view showing a display state by a fourthexample of the liquid crystal display device used in the timepieceaccording to the present invention;

FIG. 9 is a schematic cross-sectional view taken along a line IX—IX inFIG. 8;

FIG. 10 is a block diagram showing a configuration of a liquid crystaldisplay panel driving system of the liquid crystal display device shownin FIG. 8 and FIG. 9;

FIG. 11 is a schematic plan view showing a solar battery unit of a fifthstructural example of the liquid crystal display device used in thetimepiece according to the present invention;

FIG. 12 is an enlarged view of a portion surrounded by a circle XII inFIG. 11;

FIG. 13 is a schematic side view of a liquid crystal display device inwhich a solar battery unit shown in FIG. 11 is combined with a liquidcrystal display panel and an auxiliary light source;

FIG. 14 is a schematic plan view showing a part of a portionconstituting a solar battery unit of a sixth structural example of theliquid crystal display device used in the timepiece according to thepresent invention;

FIG. 15 is a schematic plan view showing electrodes and a thin filmtransistor for one pixel of the liquid crystal display panel in theliquid crystal display device of the same;

FIG. 16 is a schematic cross-sectional view of the liquid crystaldisplay device taken along a line XVI—XVI in FIG. 14 and FIG. 15;

FIG. 17 is a schematic plan view of a part of the solar battery unitshowing a modification of the sixth structural example of the liquidcrystal display device;

FIG. 18 is a schematic plan view showing a part of a portionconstituting a solar battery unit of a seventh structural example of theliquid crystal display device used in the timepiece according to thepresent invention;

FIG. 19 is a schematic plan view showing electrodes and a thin filmdiode for one pixel of the liquid crystal display panel in the liquidcrystal display device of the same;

FIG. 20 is a schematic plan view showing a second embodiment of thetimepiece according to the present invention;

FIG. 21 is a schematic cross-sectional view taken along a line XXI—XXIin FIG. 20;

FIG. 22 is a schematic plan view of only a solar battery unit 120 inFIG. 20 and FIG. 21;

FIG. 23 is a partially enlarged view showing a part near a secondelectrode connecting portion 164 of the solar battery unit shown in FIG.22;

FIG. 24 is a schematic cross-sectional view taken along a line XXIV—XXIVin FIG. 23;

FIG. 25 is a schematic plan view enlarging and showing a central portionof the solar battery unit shown in FIG. 22;

FIG. 26A, FIG. 26B and FIG. 26C are schematic plan views separatelyshowing a second electrode, a power generating semiconductor layer and afirst electrode constituting a power generation portion of the solarbattery unit shown in FIG. 25;

FIG. 27 is a schematic plan view enlarging and showing anotherstructural example of the power generation portion at the centralportion of the solar battery unit;

FIG. 28 is a cross-sectional view enlarging and showing a part of theliquid crystal display device constituted by the liquid crystal displaypanel 90 and the solar battery unit 120 shown in FIG. 21;

FIG. 29 is a cross-sectional view similar to FIG. 21, showing a thirdembodiment of the timepiece according to the present invention;

FIG. 30 is a cross-sectional view similar to FIG. 21, showing only aninner module of a fourth embodiment of the timepiece according to thepresent invention;

FIG. 31 is a cross-sectional view similar to FIG. 30, showing only aninner module of a fifth embodiment of the timepiece according to thepresent invention;

FIG. 32 is a cross-sectional view similar to FIG. 30, showing only aninner module of a sixth embodiment of the timepiece according to thepresent invention;

FIG. 33 is an enlarged plan view of a pixel portion and its surroundingsshowing another example of the liquid crystal display device used in thetimepiece according to the present invention;

FIG. 34 is an enlarged plan view of a pixel portion and its surroundingsshowing still another example of the liquid crystal display device usedin the timepiece according to the present invention;

FIG. 35 is a schematic plan view showing an example of a conventionaltimepiece with solar batteries; and

FIG. 36 is a schematic cross-sectional view taken along a lineXXXVI—XXXVI in FIG. 35.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of a timepiece according to thepresent invention are explained with reference to the drawings.

First Embodiment of Timepiece: FIG. 1 and FIG. 2

FIG. 1 is a schematic plan view showing the first embodiment of thetimepiece according to the present invention, and FIG. 2 is a schematiccross-sectional view taken along a line II—II in FIG. 1, in which thesame numerals are given to components identical to those in FIG. 35 andFIG. 36 of the above-described conventional example, and the descriptionthereof is omitted.

This watch is greatly different from the above-described conventionalwatch with solar batteries in that a liquid crystal display devicehaving a function of generating electric power is installed at a displayportion for time or the like in place of the conventional liquid crystaldisplay device.

More specifically, in the liquid crystal display device, a solar batteryunit 12 including a plurality of power generation portions (solarbatteries) are provided on the opposite side (lower side in FIG. 2) tothe visual recognition side of a liquid crystal display panel 9 inside awatch case 1. Light is applied to power generation portions (solarbatteries) 38 of the solar battery unit 12 through transmission portionsof the liquid crystal display panel 9 to generate electric power.

The solar battery unit 12 is described below in detail, in which fourblocks of power generation portions are formed on a common solar batterysubstrate as shown by broken lines in FIG. 1 and connected in series toenhance output voltage. Further, as shown in FIG. 2, a color film 11 isdisposed above the solar battery unit 12 to change the color of thesolar batteries, and formed with a reddish purple printed layer 50 atthe peripheral portion.

The liquid crystal display panel 9 disposed above (visual recognitionside of) the solar battery unit 12 is also described below, in which aliquid crystal layer 46 composed of a twisted nematic liquid crystalwith a twist angle of 90° is sealed in a gap between first and secondtransparent substrates 21 and 22 with a sealing portion 23 and a closingmaterial not shown, and a first polarizing film and a second polarizingfilm are disposed on the visual recognition side and on the oppositeside to the visual recognition side respectively.

An upper auxiliary light source 37 and a panel cover 25 are provided onthe visual recognition side of the peripheral potion of the liquidcrystal display panel 9 as shown in FIG. 2.

First Structural Example of Liquid Crystal Display Device: FIG. 3 toFIG. 5

Next, structures of the solar battery unit 12 and the liquid crystaldisplay panel 9 constituting the liquid crystal display device installedin this watch are explained in detail.

FIG. 3 is a schematic plan view of the solar battery unit 12, in whichthe power generation portions 38 are diagonally shaded to facilitaterecognition. FIG. 4 is a schematic plan view of the liquid crystaldisplay panel 9, and FIG. 5 is a schematic cross-sectional view of aliquid crystal display device 20 taken along a line V—V in FIG. 4.

In the solar battery unit 12 constituting a part of the liquid crystaldisplay device 20, as shown in FIG. 3 and FIG. 5, a power generatingsemiconductor layer 34 having a PIN junction made of amorphous silicon(a-Si) of P-type, 1-type, N-type and the like is sandwiched between afirst electrode (lower electrode) 31 which is provided on a solarbattery substrate 33 and a second electrode (upper electrode) 35,thereby constituting the power generation portion (solar battery) 38.

As clearly shown in FIG. 3, four blocks of the power generation portions38 are provided, and in each of the power generation portions 38, afirst electrode connecting portion 31 a and a second electrodeconnecting portion 35 a are connected to each other at a joint portion36 to increase output voltage.

Further, in order to prevent deterioration of the solar batteries, aprotection layer 30 (FIG. 5) made of a polyimide resin is provided onthe solar battery substrate 33 to cover the power generation portions38. Furthermore, in order to establish an electric connection to acircuit board 6 shown in FIG. 2, wirings are connected to the firstelectrode connecting portions 31 a and the second electrode connectingportions 35 a respectively through openings 30 a and 30 b which areformed by removing the protection layer 30 on the solar batterysubstrate 33.

The color film 11 provided above the solar battery unit 12 is providedwith the reddish purple printed layer 50 facing a portion other than thepower generation portions 38.

In the liquid crystal display panel 9 disposed on the visual recognitionside (observer side) of the solar battery unit 12, as shown in FIG. 4and FIG. 5, the liquid crystal layer composed of a twisted nematicliquid crystal with a twist angle of 90° is sealed between the first andsecond transparent substrates 21 and 22 with the sealing portion 23 anda closing material 27. Further, data electrodes 47 each made of atransparent conductive film are formed in stripes on the inner surfaceof the first substrate 21 disposed on the visual recognition side, andscanning electrodes 45 each made of a transparent conductive film areformed in stripes, perpendicular to the data electrodes 47, on the innersurface of the second substrate 22 opposed to the first substrate 21(see FIG. 4).

It should be noted that the data electrodes 47, the sealing portion 23and the closing material 27 are provided on the back side of the firstsubstrate 21, but the first substrate 21 is transparent, and thus theyare shown by solid lines in FIG. 4.

Further, as shown in FIG. 5, a first polarizing film 49 is disposed onthe outer surface (visual recognition side) of the first substrate 21and a second polarizing film 48 on the outer surface (opposite side tothe visual recognition side) of the second substrate 22, respectively.The first polarizing film 49 is an absorption-type polarizing film ofwhich one optical axis is an absorption axis and an optical axisperpendicular thereto is a transmission axis. The second polarizing film48 is a reflection-type polarizing film of which one optical axis is areflection axis and an optical axis perpendicular thereto is atransmission axis.

The first polarizing film 49 and the second polarizing film 48 arearranged so that the respective transmission axes are perpendicular toeach other, and the 90′-twisted nematic liquid crystal is used for theliquid crystal layer 46, whereby voltage is applied to the liquidcrystal layer 46 within pixel portions 26 (see FIG. 4) constituted byintersections of the data electrodes 47 and the scanning electrodes 45to control transmittance and reflectance, thereby performing a display.

The arrangement of the transmission axes of the first polarizing film(absorption-type polarizing film) 49 and the second polarizing film(reflection-type polarizing film) 48 to be perpendicular to each otherbrings about a transmission state by combination with the liquid crystallayer 46 when the voltage to the liquid crystal display panel 9 is off.Therefore, it becomes easy to apply light to the solar battery unit 12while the liquid crystal display device 20 is not in use, therebyelectric power is efficiently generated.

Further, the color film 11 having characteristics of transmitting lightwithin a wavelength region matching with wavelengths absorbed by thepower generation portions 38 of the solar battery unit 12 is providedbetween the liquid crystal display panel 9 and the solar battery unit12.

A display by the liquid crystal display panel 9 is performed usingtransmission characteristics of the color film 11 having substantiallythe same transmission characteristics (spectral reflectioncharacteristics) as absorption wavelength characteristics of the solarbattery unit 12 caused by an increase in the transmittance, andreflection characteristics caused by an increase in reflectance. Theprinted layer 50 provided at a portion of the color film 11 facing theportion other than the power generation portions 38 on the solar batteryunit 12 further increases the uniformity in the display by the liquidcrystal display panel 9.

As described above, the reflection-type polarizing film is used as thesecond polarizing film 48, and the liquid crystal display panel 9 isgiven reflection characteristics, and, further, the display is performedusing the absorption characteristics of the solar battery unit 12 andthe color film 11, and the solar battery unit 12 is disposed on the backside of the liquid crystal display panel 9. Furthermore, the color film11 which transmits light with substantially the same wavelengths as thewavelengths absorbed by the power generation region of the solar batteryunit 12 is provided between the liquid crystal display panel 9 and thesolar battery unit 12 and provided with the printed layer 50, therebymaking it possible to bring the entire surface of the solar battery unit12 to substantially the same color.

More than that, the solar battery unit 12 can be disposed on the backside of the liquid crystal display panel 9 without decreasing the powergeneration efficiency of the solar battery unit 12.

Moreover, the color film 11 is provided over the periphery of a displayregion (a region larger than the second substrate 22 shown in FIG. 4)constituted of clusters of the pixel portions 26 which are constitutedby the intersections of the data electrodes 47 and the scanningelectrodes 45 of the liquid crystal display panel 9, making it possibleto make the display by the liquid crystal display panel 9 uniform.

Second Structural Example of Liquid Crystal Display Device: FIG. 6

Next, the second structural example of the liquid crystal display deviceinstalled in the timepiece according to the present invention isexplained with FIG. 6. FIG. 6 is a cross-sectional view, similar to FIG.5 of the first structural example, showing the structure of the liquidcrystal display device, in which the same numerals are given to portionscorresponding to those in FIG. 5.

In the liquid crystal display device 20, different from the firststructural example, only a printed layer 50 is provided on a solarbattery unit 12 with no color film 11 provided between a liquid crystaldisplay panel 9 and the solar battery unit 12.

The solar battery unit 12 is constituted similarly to the firststructural example, but a solar battery substrate 33 is not providedwith a protection layer 30 thereon but with the printed layer 50 at aportion except for power generation portions 38.

In the liquid crystal display panel 9 disposed on the visual recognitionside of the solar battery unit 12, a super twisted nematic liquidcrystal with a twist angle of 240° is used as a liquid crystal layer 46sealed between first and second transparent substrates 21 and 22.Further, a retardation film 41 is disposed between the first substrateand a first polarizing film 49 made of an absorption-type polarizingfilm, and a cholesteric liquid crystal film 58 for selectivelyreflecting light within a predetermined wavelength region of visiblelight is provided on the outer surface (opposite side to the visualrecognition side) of the second substrate 22.

The first substrate 21, the first polarizing film 49 and the retardationfilm 41 are bonded together so that optical axes of the first polarizingfilm 49 made of the absorption-type polarizing film and the retardationfilm 41 are arranged to have an offset in angle, and that an orientationaxis of the liquid crystal layer 46 composed of the super twistednematic liquid crystal, an absorption axis of the first polarizing film49 and a retardation axis of the retardation film 41 are arranged tohave offsets in angle. Then, the angle of the cholesteric liquid crystalfilm 58 bonded to the second substrate 22 is arranged so thattransmittance becomes a maximum when no voltage is applied.

This brings the liquid crystal display panel 9 to a transmission statewhen the applied voltage is off, thereby facilitating application oflight to the solar battery unit 12 when the liquid crystal displaydevice is not in use, electric power is efficiently generated.

The display by the liquid crystal display panel 9 is performed usingabsorption characteristics by the solar battery unit 12 and the printedlayer 50 which has substantially the same absorption wavelengthcharacteristics (spectral reflection characteristics) as those of thesolar battery unit 12 caused by an increase in the transmittance, and,further, using selective reflection by the cholesteric liquid crystalfilm 58 caused by an increase in the voltage applied to the liquidcrystal layer 46, and using reflection characteristics caused by anincrease in reflectance. The formation of the printed layer 50 on thesolar battery unit 12 can bring the power generation portions 38 of thesolar battery unit 12 and the solar battery substrate 33 therearound tothe same color tone, presenting a uniform color when the solar batteryunit 12 is used as an absorption plate of the liquid crystal displaypanel 9. Further, the printed layer 50 is formed directly on the solarbattery unit 12, resulting in improved alignment accuracy.

Furthermore, a wavelength of the selective reflection by the cholestericliquid crystal film 58 is brought into a complementary colorrelationship with a wavelength contributing to power generation of thesolar battery unit 12, whereby light with the wavelength contributing tothe power generation of the solar battery unit 12 transmits thecholesteric liquid crystal film 58 even during the selective reflectionof the cholesteric liquid crystal film 58 and is made incident on thesolar battery unit 12, thereby improving the power generation efficiencyand enhancing contrast ratio.

Third Structural Example of Liquid Crystal Display Device: FIG. 7

Next, the third structural example of the liquid crystal display deviceinstalled in the timepiece according to the present invention isexplained with FIG. 7. FIG. 7 is a cross-sectional view, similar to FIG.5 of the first structural example, showing the structure of the liquidcrystal display device, in which the same numerals are given to portionscorresponding to those in FIG. 5.

This liquid crystal display device 20 is different from the firststructural example in that a mixed liquid crystal layer 56 with ascattering property containing a liquid crystal and a polymer which is atransmitting polymer solid substance is used as the liquid crystal layerwhich is sealed between first and second transparent substrates of aliquid crystal display panel 9.

Further, the outer surface (visual recognition side) of a firstsubstrate 21 is not provided with a first polarizing film 49 but anultraviolet light cut film 57 for preventing application of ultravioletlight to the mixed liquid crystal layer 56. Furthermore, no secondpolarizing film 48 is disposed on the outer surface of the secondsubstrate, and no color film 11 is provided between the second substrateand a solar battery unit 12, but a printed layer 50 is provided directlyon the outer surface of a second substrate 22.

The display by the liquid crystal display panel 9 is performed using theabsorption characteristics by the solar battery unit 12 and the printedlayer 50 which is provided on the back side of the second substrate 22and has substantially the same absorption wavelength characteristics(spectral reflection characteristics) as those of the solar battery unit12 caused by an increase in the transmittance, and, further, an increasein the voltage applied to the mixed liquid crystal layer 56 enhances ascattering property caused by a difference in refractive index betweenthe liquid crystal and the transmitting polymer solid substance, therebycausing a scattering in white.

The formation of the printed layer 50 on the second substrate 22 canbring power generation portions 38 of the solar battery unit 12 and asolar battery substrate 33 therearound to the same color tone,presenting a uniform color when the solar battery unit 12 is used as theabsorption plate of the liquid crystal display panel 9.

Further, the printed layer 50 is closely contacted the second substrate22 and thus a distance between the mixed liquid crystal layer 56 and theprinted layer 50 becomes short, thereby preventing blurring of an imagecaused by double images.

Further, the mixed liquid crystal layer 56 containing the liquid crystaland the polymer which is the transmitting polymer solid substance isused for the liquid crystal layer, and its scattering property iscontrolled to perform a display, thereby increasing a contrast ratiowith respect to a color absorbed by the solar battery unit 12,representing a bright display. Moreover, no polarizing film is used,thereby increasing the transmittance of the liquid crystal displaypanel, resulting in improved power generation efficiency of the solarbattery unit 12.

A liquid crystal display panel having the same structure as that of thethird structural example can also be constituted using a mixed liquidcrystal layer made by mixing a liquid crystal and a dichroic dye for itsliquid crystal layer. In this case, an absorption wavelength of thedichroic dye is given at least a difference of 0.1 on a chromaticitydiagram (x, y) with respect to the absorption wavelength of the powergeneration portions 38 of the solar battery unit 12 or the printed layer50, thereby improving visibility. In the liquid crystal display panelusing the dichroic dye, no polarizing film is used, also improving thepower generation efficiency of the solar battery unit 12.

Fourth Structural Example of Liquid Crystal Display Device: FIG. 8 toFIG. 10

Next, the fourth structural example of the liquid crystal display deviceinstalled in the timepiece according to the present invention isexplained with FIG. 8 to FIG. 10. This liquid crystal display device isconfigured such that when the quantity of power generation of a solarbattery unit decreases, display contents on a liquid crystal displaypanel are changed to increase the quantity of application of light tothe solar battery unit, thereby making it possible to control thequantity of power generation of the solar battery unit.

FIG. 8 is a schematic plan view showing a display state of the liquidcrystal display device, and FIG. 9 is a schematic cross-sectional viewtaken along a line IX—IX in FIG. 8. In these drawings, the same numeralsare given to portions corresponding to those in FIG. 3 and FIG. 5 of thefirst structural example.

The liquid crystal display device 20, as shown in FIG. 8 and FIG. 9,includes a liquid crystal display panel 9 and a solar battery unit 12,in which a color film 59 is disposed on the visual recognition side ofan electrode portion (including wirings) of the solar battery unit 12between the liquid crystal display panel 9 and the solar battery unit12, for shielding the electrode portion. The color film 59 is a filmhaving substantially the same spectral reflectance as that of theabove-described power generation portion of the solar battery unit 12.

The liquid crystal display panel 9 is constituted by, from the visualrecognition side, an absorption-type polarizing film (not shown), afirst substrate 21, data electrodes and an alignment film (not shown), aliquid crystal layer 46, an alignment film and scanning electrodes (notshown), a second substrate 22, and a reflection-type polarizing film(not shown). The liquid crystal layer 46 is sealed between the firstsubstrate 21 and the second substrate 22 with a sealing portion 23 and aclosing material 27.

A whole display region 52 of the liquid crystal display panel 9 isconstituted of clusters of pixel portions which are the intersections ofthe data electrodes on the first substrate 21 and the scanningelectrodes on the second substrate 22. The whole display region 52 isconstituted of an upper display region 53 and a lower display region 54,and a transmission region 55 provided around the upper display region 53and the lower display region 54. Further, in this example, the solarbattery unit, the printed layer and the color film are used for a darkdisplay as in the above-described liquid crystal display devices,requiring no panel cover around the whole display region 52 inparticular, and thus a structure is employed in which the color film 59is disposed also around the solar battery unit 12 in place of the panelcover to increase the quantity of power generation.

A system block diagram for changing the display regions shown in FIG. 8of the liquid crystal display panel 9 in the liquid crystal displaydevice 20 is shown in FIG. 10.

As shown in FIG. 10, the quantity of power generation by electric energyconverted from light energy by the solar battery unit 12 which is apower generation means is detected by a voltage detection circuit 82 andconverted to a predetermined voltage by a charging voltage conversioncircuit 83 in accordance with the quantity of power generation andaccumulated in a secondary battery 84 which is a storage battery.Further the voltage detection circuit 82 detects the quantity of powergeneration of the solar battery unit 12 and a battery remaining capacityof the secondary battery 84, and a display region selection circuit 85determines the number of scanning lines used for a display in accordancewith the detection result.

Further, a synchronization separation circuit 87 divides asynchronization signal in an image signal outputted from an image signaloutput circuit 88 into a vertical synchronization signal to be inputtedinto a vertical synchronization circuit 81 and a horizontalsynchronization signal to be inputted into a horizontal synchronizationcircuit 91 with reference to a reference clock generated by a referenceclock oscillation circuit 86.

The image signal from the image signal output circuit 88 is inputtedinto a gradation signal generation circuit 92 through an A/D converter89, and combined with the vertical synchronization signal from thevertical synchronization circuit 81 and inputted into a data electrodedrive circuit 93, where driving signals are generated and applied to thedata electrodes of the liquid crystal display panel 9.

On the other hand, signals for the number of the scanning lines whichare selected by the display region selection circuit 85 are inputtedinto the scanning electrode drive circuit 94 through the horizontalsynchronization circuit 91, and the scanning signals generated in thescanning electrode drive circuit 94 are applied to the scanningelectrodes of the liquid crystal display panel 9.

Of the whole display region 52 of the liquid crystal display panel 9constituted by the first substrate 21, the second substrate 22, theliquid crystal layer and the like, the upper display region 53 alwaysperforms a display as a display region selected by the display regionselection circuit 85, and the lower display region 54 stops performing adisplay as required to increase the transmittance, thereby improvingpower generation efficiency of the solar battery unit 12.

As described above, the number of the scanning lines contributed to thedisplay is selected by the display region selection circuit 85 inaccordance with the quantity of power generation of the solar batteryunit 12 or the battery remaining capacity of the secondary battery 84,and the whole display region 52 is divided into the region 53 where adisplay is performed and the region 54 where a display is stopped toincrease the transmittance to control the transmittance of the liquidcrystal display panel 9, thereby making it possible to control thequantity of power generation of the solar battery unit 12.

Further, in the liquid crystal display device, the liquid crystaldisplay panel 9 is configured so that its transmittance becomes highwhere no voltage is applied thereto for both improvement of thetransmittance of the liquid crystal display panel 9 and reduction inpower consumption thereof.

For example, in the case in which the absorption-type polarizing film,the reflection-type polarizing film and the twisted nematic liquidcrystal layer are used, the absorption-type polarizing film and thereflection-type polarizing film are arranged so that the respectivetransmission axes are perpendicular to each other. Further, in the casein which the mixed liquid crystal layer containing a dichroic dye in aliquid crystal is used, the dichroic dye is aligned in a direction ofless absorption when no voltage is applied thereto. In the case in whichthe mixed liquid crystal layer containing a transmitting polymer solidsubstance in a liquid crystal is used, a mode in which the transmittanceincreases when no voltage is applied thereto is employed.

Fifth Structural Example of Liquid Crystal Device: FIG. 11 to FIG. 13

Next, as the fifth structural example of the liquid crystal displaydevice installed in the timepiece according to the present invention, aliquid crystal display device provided with a solar battery unitincluding a solar battery substrate 33 which is a transparent substrate,a power generation region for absorbing light to generate electric powerand a transmission region for transmitting light is explained using FIG.11 to FIG. 13.

FIG. 11 is a schematic plan view of the solar battery unit having thepower generation regions and the transmission regions, and FIG. 12 is anenlarged view of a part enclosed in a circle D in FIG. 11. FIG. 13 is aschematic side view of a liquid crystal display device in which thesolar battery unit shown in FIG. 11 is combined with a liquid crystaldisplay panel and an auxiliary light source.

In a solar battery unit 60 shown in FIG. 11 and FIG. 12, a plurality offirst electrodes (lower electrodes) 62 each made of an indium tin oxide(ITO) film which is a transparent conductive film and a plurality ofsecond electrodes (upper electrodes) 63 each similarly made of an indiumtin oxide (ITO) film which is a transparent conductive film are formedin stripes on a transparent solar battery substrate 43 so that the firstelectrodes 62 are perpendicular to the second electrodes 63. Atintersections of the first electrodes 62 and the second electrodes 63,power generating semiconductor layers 34 each of which is isolated likean island and made of an amorphous silicon (a-Si) film having a PINjunction are provided to be sandwiched between the first electrodes 62and the second electrodes 63, thereby constituting power generationportions 61 as the power generation regions respectively.

The plurality of the first electrodes 62 are connected to each other,and the plurality of the second electrodes 63 are connected to eachother, thereby making it possible to obtain predetermined voltage andcurrent by power generation of the power generation portions 61. Regionsother than the power generation portions 61 on the transparent solarbattery substrate 43, in which only the first transparent electrodes 62and the second transparent electrodes 63 are formed on the transparentsolar battery substrate 43, are transmission regions for transmittinglight.

Therefore, as shown in FIG. 13, any of the liquid crystal display panels9 shown in the above-described structural examples is disposed on thevisual recognition side of the solar battery unit 60, and an auxiliarylight source 80 is disposed on the opposite-surface side to the surfacefacing the liquid crystal display panel 9 of the solar battery unit 60,so that light from the auxiliary light source 80 is applied to theliquid crystal display panel 9 through the transmission regions of thesolar battery unit 60, enabling a bright display even when there is noexternal light or short of light at night or the like.

In this case, it is preferable that the power generation regions (thepower generation portions 61) of the solar battery unit 60 are providedat positions facing non-display regions around the display pixelportions of the liquid crystal display panel 9, and the transmissionregions are provided at positions facing the display pixel portions ofthe liquid crystal display panel 9.

Alternatively, it is also preferable that the power generation regions(the power generation portions 61) of the solar battery unit 60 areprovided at least at positions facing the panel cover portion around thedisplay region of the liquid crystal display panel 9, and thetransmission regions are provided at positions facing the inside of thedisplay region of the liquid crystal display panel 9.

Sixth Structural Example of Liquid Crystal Display Panel: FIG. 14 toFIG. 16

Next, the sixth structural example of the liquid crystal display deviceinstalled in the timepiece according to the present invention isexplained with FIG. 14 and FIG. 16. This liquid crystal display deviceis constituted by installing a solar battery unit into a liquid crystaldisplay panel with thin film transistors (TFT), each of which is athree-terminal type active element as a nonlinear element for switchinga signal to a pixel portion, provided on one of substrates (activesubstrates) sandwiching a liquid crystal layer.

FIG. 14 is a schematic plan view showing a part of a portionconstituting the solar battery unit in the liquid crystal displaydevice, FIG. 15 is a schematic plan view showing electrodes and the thinfilm transistor for one pixel of the liquid crystal display panel, andFIG. 16 is a schematic cross-sectional view of the liquid crystaldisplay device taken along a line XVI—XVI in FIG. 14 and in FIG. 15.

The solar battery unit shown in FIG. 14 has the same structure as thatof the solar battery unit 60 in the fifth structural example shown inFIG. 11 and FIG. 12, in which power generating semiconductor layers 34each made of an amorphous silicon (a-Si) film are sandwiched atintersections of a plurality of first electrodes 62 and a plurality ofsecond electrodes 63 respectively, thereby constituting a large numberof power generation portions (solar batteries) 61.

However, in this solar battery unit, as shown in FIG. 16, a secondtransparent substrate 22 (a substrate disposed on the opposite side tothe visual recognition side) of a liquid crystal display panel 9′ alsoserves as a solar battery substrate, and, the first electrodes 62, thepower generating semiconductor layers 34 and the second electrodes 63which are described above are formed on the second substrate 22, therebyproviding the large number of the power generation portions (solarbatteries) 61 at positions facing non-display regions around the displaypixel portions of the liquid crystal display panel 9′.

Further, a transparent insulating film 72 is formed over the entiresurface of the second substrate formed with the solar battery unit, andscanning electrodes 64, data electrodes 65, display electrodes 68 andthin film transistors 70 which are shown in FIG. 15 are formed on theinsulating film 72.

More specifically, the scanning electrodes 64 are arranged above thefirst electrodes 62 of the solar battery unit, and the data electrodes65 are arranged above the second electrodes 63. The scanning electrode64 is formed with a gate electrode 69 protruding, a gate insulating film(not shown) is disposed on the gate electrode 69, and an amorphoussilicon (a-Si) film 71 is formed on the gate insulating film. Further,the data electrode 65 is disposed above the second electrode 63 of thesolar battery unit, a source electrode 66 connecting to the dataelectrode is provided extending onto the amorphous silicon (a-Si) film71, and a drain electrode 67, which is provided on the amorphous silicon(a-Si) film 71 with a predetermined gap interposed with respect to thesource electrode 66, is provided extending from the display electrode68. The insulating film not shown is formed on the front face of thescanning electrode 64 to prevent direct conduction to the data electrode65 at the intersection.

The display electrode 68, as shown in FIG. 15, is formed of an indiumtin oxide (ITO) film which is a transparent conductive film above theinsulating film 72 almost entirely within each region of one pixelsurrounded by the scanning electrodes 64 and the data electrodes 65.

An amorphous silicon (a-Si) film (not shown) containing impurity ions isprovided between the amorphous silicon (a-Si) film 71 and the sourceelectrode 66 or the drain electrode 67.

The above-described gate electrode 69, amorphous silicon (a-Si) film 71,source electrode 66, drain electrode 67 and the like constitute the thinfilm transistor (TFT) as a nonlinear element for switching a signal tothe display electrode which is the pixel portion.

A liquid crystal layer 46 composed of a twisted nematic liquid crystalis sealed between the second substrate 22 formed with theabove-described components and the first substrate with opposedelectrodes 73 each made of an indium tin oxide (ITO) film, which is atransparent conductive film, formed on the entire inner surface thereofopposed to the second substrate 22, and a first polarizing film (anabsorption-type polarizing film) 49 is disposed on the visualrecognition side of the first substrate 21 and a second polarizing film(reflection-type polarizing film) 48 is disposed on the opposite side tothe visual recognition side of the second substrate 22, therebyconstituting the liquid crystal display panel 9′ having a function ofgenerating electric power.

A predetermined voltage is applied between the scanning electrode 64 andthe data electrode 65 of this liquid crystal display panel 9′ to apply avoltage between the display electrode 68 and the opposed electrode 73which is disposed opposed thereto with the liquid crystal layer 46interposed therebetween, thereby performing a display. Since the liquidcrystal layer 46 around the display electrode 68 has no change bysignal, an effective display can not be performed there. Therefore, thefirst electrodes 62 and the second electrodes 63 of the solar batteryunit are arranged around the display electrode 68.

Further, the power generating semiconductor layer 34 is disposed on theback side of the scanning electrode 64 and the data electrode 65 whichare transparent electrodes connected to each other through the thin filmtransistor (TFT), thereby supplying predetermined light energy to thesolar battery unit without influence exerted upon its displayperformance.

Further, as shown in FIG. 16, for example, an electro-luminescent light(EL) is disposed on the opposite side (lower side in FIG. 16) to thevisual recognition side of the liquid crystal display panel 9′ as anauxiliary light source 80, thereby making it possible to apply lightemitted by the auxiliary light source 80 to the visual recognition sidethrough the transmission regions of the solar battery unit.

Accordingly, in a bright environment, external light of a liquid crystaldisplay device 20 is applied to the power generation portions 61 of thesolar battery unit, thereby generating electric power. Further, when theoutside is dark, the auxiliary light source 80 is turned on, the lightemitted by the auxiliary light source 80 is applied to the visualrecognition side through the transmission portions of the solar batteryunit, thereby enabling a bright display.

Modification of Sixth Structural Example: FIG. 17

The solar battery unit may be structured as shown in FIG. 17 as apartially changed example of the sixth structural example. Incidentally,the same numerals are given to portions in FIG. 17 corresponding tothose in FIG. 14. The structures of the scanning electrode 64, the dataelectrode 65 and the thin film transistor 70 of the liquid crystaldisplay panel overlapped on the solar battery unit through theinsulating film are the same as those shown in FIG. 15.

In the solar battery unit, the first electrodes (lower electrodes) 62formed on the second substrate 22 of the liquid crystal display panel 9′are partially arranged in a lattice shape as shown by broken lines inFIG. 17 with parts thereof in stripes extending in a vertical directionin the drawing partially cut off. In other words, FIG. 17 just shows aboundary part between the cut-off part and the lattice part.

On the first electrodes 62, a power generating semiconductor 34 made ofan amorphous silicon (a-Si) film is formed on the entire region exceptfor the display electrodes 68 shown in FIG. 15, on which the secondelectrodes (upper electrodes) 63 are formed in vertical stripes tooverlap the vertical parts of the first electrodes 62, therebyconstituting the power generation portions (solar batteries) 61.

Such an arrangement of the first electrodes 62 in a lattice shape andthe power generating semiconductor layer 34 to cover the entire surfacethereof can increase the effective area of the power generation portions61, thereby increasing power generation output.

The reason why the first electrodes 62 are not entirely in a latticeshape as shown in FIG. 17 is that the mutual connection between blockscomposed of a plurality of the first electrodes 62 makes it possible toobtain a predetermined voltage or electric current.

Also in this case, the arrangement of an auxiliary light source such asan electro-luminescent light (EL) on the back side of the liquid crystaldisplay panel 9′ equipped with the solar battery unit makes it possibleto apply light of the auxiliary light source to the visual recognitionside through an opening of the solar battery unit, thereby enabling abright display by turning on the auxiliary light source even when theoutside is dark.

Further, the power generating semiconductor layer 34 is disposed in alattice shape to cover ineffective regions for display around thedisplay electrodes 68, thereby enabling to block light to theineffective regions for display when the auxiliary light source isturned on, and improving the display quality.

Seventh Structural Example of Liquid Crystal Display Device: FIG. 18 andFIG. 19

Next, the seventh structural example of the liquid crystal displaydevice installed in the timepiece according to the present invention isexplained with FIG. 18 and FIG. 19. This liquid crystal display deviceis constituted by installing a solar battery unit into a liquid crystaldisplay panel with thin film diodes (TFD), each of which is atwo-terminal type active element as a nonlinear element for switching asignal to a pixel portion, provided on one of substrates (activesubstrates) sandwiching a liquid crystal layer.

FIG. 18 is a schematic plan view showing a part of a portionconstituting the solar battery unit in the liquid crystal displaydevice, and FIG. 19 is a schematic plan view showing electrodes and thethin film diode for one pixel of the liquid crystal display panel, inwhich a cross section corresponding to the above-described FIG. 16 isthe same as FIG. 16 except that there is no scanning electrode 64, andthat opposed electrodes 73 are formed in belts at positions facingdisplay electrodes.

In this solar battery unit, first electrodes (lower electrodes) 62 arearranged in a lattice shape on a second substrate 22 of the liquidcrystal display panel, power generating semiconductor layers 34 eachmade of an amorphous silicon (a-Si) film are formed in horizontalstripes on horizontal stripe portions of the first electrodes 62, andfurther, second electrodes (upper electrodes) 63 are arranged on thepower generating semiconductor layers 34.

The above-described arrangement of the first electrodes 62 in a latticeshape and the power generating semiconductor layers 34 in horizontalstripes can increase the effective area of power generation portions 61.The reason why the power generating semiconductor layer 34 ishorizontally arranged is that a data electrode (vertical electrode) 65is connected to the thin film diode 75 shown in FIG. 19. If the thinfilm diode 75 is connected to a scanning electrode (horizontalelectrode), it is desirable to form the power generating semiconductorlayer 34 in a vertical stripe in viewpoint of prevention of decrease inefficiency of the solar battery unit due to non-transmission of wiringconnected to the thin film diode 75.

A transparent insulating film (not shown) is formed over the entiresurface of the second substrate formed with the solar battery unit asdescribed above. Further, the data electrodes 65 each made of a tantalum(Ta) film are arranged in vertical stripes to overlap the verticalstripe portions of the first electrodes 62 of the solar battery unit onthe insulating film as shown in FIG. 19, and a display electrode 68 madeof an indium tin oxide (ITO) film is arranged between the adjacent dataelectrodes 65.

A lower electrode 76 is extended from the data electrode 65 toward thedisplay electrode, and a tantalum oxide (Ta₂O₅) film (not shown) made byanodizing a tantalum film is formed on the lower electrode 76 as anonlinear resistance layer. Further, an upper electrode 77 is extendedfrom the display electrode 68 to intersect the lower electrode 76through the nonlinear resistance layer.

The lower electrode 76, the tantalum oxide film and the upper electrodeconstitute the thin film diode (TFD) 75.

A predetermined voltage is applied to the data electrode 65 to apply avoltage between the display electrode 68 and an opposed electrode (notshown) which is disposed with the liquid crystal layer interposedtherebetween, and thus the liquid crystal layer around the displayelectrode 68 has no change by signal, an effective display can not beperformed there. Therefore, the first electrodes 62 and the secondelectrodes 63 of the solar battery unit are arranged around the displayelectrode 68. Further, since the transparent conductive film is used forthe opposed electrode, the arrangement of the power generatingsemiconductor layer 34 in a direction perpendicular to the dataelectrode 65 makes it possible to supply predetermined light energy tothe solar battery unit without influence exerted upon the displayperformance.

Furthermore, as in the sixth structural example shown in FIG. 16, anauxiliary light source such as an electro-luminescent light (EL) isdisposed on the opposite side to the visual recognition side of theliquid crystal display panel equipped with the liquid crystal displaypanel also in this structure, thereby making it possible to apply lightemitted by the auxiliary light source to the visual recognition sidethrough the transmission regions of the solar battery unit, whereby evenwhen the outside is dark, a bright display becomes possible by turningon the auxiliary light source.

It should be noted that the first electrodes 62 of the solar batteryunit are partially arranged in a lattice shape with parts thereof cutoff, and blocks composed of a plurality of the first electrodes 62 aremutually connected, thereby making it possible to obtain a predeterminedvoltage or electric current also in this structure.

Operation and Effect of Each Structural Example of Liquid CrystalDisplay Device

In each liquid crystal display device having the above-describedfunction of generating electric power installed in the timepieceaccording to the present invention, solar batteries are arranged on theopposite side to the visual recognition side of the liquid crystaldisplay panel, whereby the whole or a part of energy consumed by itsliquid crystal display panel or the liquid crystal display device can beobtained by converting light energy to electric energy by means of thesolar batteries.

The use of a reflection color or an absorption color of the solarbattery for the display by the liquid crystal display panel can preventblockage of light to the power generation regions of the solar battery,never decreasing the power generation efficiency of the solar battery.

In order to correct the difference in color tone between the powergeneration region and the electrode region therearound of the solarbattery unit or region where the substrate surface is exposed, theprinted layer with an ink of the same color as the color tone of thepower generation region is provided outside the power generation region.Thereby, when the solar battery unit is used as the reflection color orthe absorption color of the liquid crystal display panel, a reflectionsurface or an absorption surface is in a uniform color tone, therebymaking the liquid crystal display panel into a uniform display color.

When the power generation region of the solar battery unit is used asthe display color, it is necessary to apply light to the solar batteryunit which is disposed at the back of the liquid crystal display panelwithout deterioration of the liquid crystal within the power generationregion. In other words, light with a wavelength much shorter than thatof the visible light is not preferable because ultraviolet light causesdeterioration of the liquid crystal layer, and conversely light with awavelength much longer than that of the visible light causes absorptionby the liquid crystal layer.

When the power generation region effectively absorbs the visible lightto generate electric power, absorption of the visible light withoutreflection occurs. Therefore, the use of the solar battery unit for thedisplay of the liquid crystal display panel means the use of the solarbattery unit as an absorbing plate. Accordingly, a bright display isrequired of the liquid crystal display panel to improve the contrastratio of the liquid crystal display panel.

When the liquid crystal display panel disposed above the solar batteryunit performs a display using polarizing films, the use of thereflection-type polarizing film as the polarizing film disposed on theopposite side to the visual recognition side enables utilization of thereflection characteristics and transmission characteristics, presentinga bright reflection display and a dark display through the use of thesolar battery unit.

Further, in the liquid crystal display panel using the liquid crystallayer composed of a guest-host liquid crystal that is the mixed liquidcrystal composed of a liquid crystal and a dichroic dye, a difference ofat least 0.1 or more on a chromaticity diagram (x, y) is given betweenthe absorption color of the dichroic dye and the absorption color of thesolar battery unit, thereby enabling recognition.

The liquid crystal display panel using the liquid crystal layer composedof the scattering-type mixed liquid crystal containing a transmittingpolymer solid substance in a liquid crystal enables a bright display byvirtue of the blocking effect of the solar battery unit and scatteringby the mixed liquid crystal. In this case, since the transmittance islarge as compared to a display using another liquid crystal layer, thedisplay region can be changed in accordance with a decrease in the powergeneration efficiency of the solar battery unit due to a decrease inexternal light or a necessity of charge of energy to the liquid crystaldisplay device, thereby controlling the quantity of application of lightto the solar battery unit. The use of a large transmittance enablesimprovement of the power generation efficiency of the solar batteryunit.

Further, the power generation regions and the transmission regions areprovided in the same substrate in the solar battery unit, and thetransmission regions are matched with the display regions of the liquidcrystal display panel, thereby improving both the power generationefficiency and the display quality.

Furthermore, it becomes possible to apply light from the auxiliary lightsource which is disposed on the back side of the solar battery unitthrough the use of the opening of the solar battery unit, whereby theliquid crystal display panel can be used as a transmission-type liquidcrystal display panel.

The printed layer for shielding the difference in color tone between thepower generation region and its surroundings of the solar battery unitcan be provided on the solar battery unit. In particular, the provisionof the printed layer on the reflection-type polarizing film or on thecholesteric liquid crystal film used for constitution of the liquidcrystal display panel is effective in making the display uniform becausethe surfaces of them are flat as compared to the surface of the solarbattery unit and bonding it to the liquid crystal display panel causesno distortion.

The liquid crystal display device having such a function of generatingelectric power is suitable for a display device of an electronic deskcalculator or a portable information instrument. Further, the liquidcrystal display device is applied to a timepiece that has a severelimitation of power consumption, in which the printed layer brings thecolors of the electrode portion of the solar battery and its powergenerating semiconductor layer into the same color tone. This isextremely effective in the timepiece for which decoration is important.

The combination of the printed layer and the color film can make thesolar battery unobtrusive to a user of the device. Further, the liquidcrystal display device equipped with the solar battery unit in which thesolar batteries (power generation portions) are arranged in a matrix orin stripes to provide the transmission portions is used for a timepiece,thereby making it possible to use a surface emission-type auxiliarylight source such as an EL, enabling a bright display by turning on theauxiliary light source even in a dark environment and making thetimepiece thinner.

Second Embodiment of Timepiece: FIG. 20 to FIG. 28

Next, the second embodiment of the timepiece according to the presentinvention is explained with reference to FIG. 20 to FIG. 28 of thedrawings.

A liquid crystal display device installed in a timepiece described belowis, different from the liquid crystal display devices installed in thetimepiece of the first embodiment which have been explainedhereinbefore, structured so that a solar battery unit havingtransmission portions and power generation portions is disposed on thevisual recognition side of the liquid crystal display panel so as torecognize a display by the liquid crystal display panel through thetransmission portions.

FIG. 20 is a schematic plan view of a wristwatch equipped with theliquid crystal display device having the function of generating electricpower, and FIG. 21 is a schematic cross-sectional view taken along aline XXI—XXI in FIG. 20. FIG. 22 is a schematic plan view of only thesolar battery unit.

This watch is, as shown in FIG. 20, a combination watch using both ananalog display in which time is indicated by an hour hand 143 and aminute hand 142 mounted on a hand shaft 141, and a digital display bythe liquid crystal display panel.

A circular solar battery unit 120 is disposed at a positioncorresponding to a dial on which hour figures 24 for indicating hours atthe front face of a watch case 100, and the hour hand 143, the minutehand 142 and a liquid crystal display panel 90 described below arearranged thereunder.

The solar battery unit 120 is formed such that power generation portions138 for absorbing light to generate electric power and transmissionportions 139 for transmitting light are alternately formed in verticalstripes almost over the entire surface thereof. The pitches of the powergeneration portions 138 are made larger near the center in thehorizontal direction in FIG. 20 to increase an area proportion of thetransmission portions 139, thereby making a display by the liquidcrystal display panel legible. The pitches of the power generationportions 138 are conversely made smaller near both ends to decrease thearea proportion of the transmission portions 139, thereby increasing thepower generation efficiency.

Further, a through hole (hand shaft hole) 145 into which the hand shaft141 is inserted is provided at the center. A mode adjusting button 10 isprovided at the side face of the watch case 100.

The liquid crystal display panel 90 under the solar battery unit 120 isprovided with a chronograph display portion 3, a year-month-date displayportion 4 and a battery remaining capacity display portion 13.

The solar battery unit 120 and the liquid crystal display panel 90 areexplained here in detail with reference to FIG. 22 to FIG. 28.

FIG. 22 is a schematic plan view of only the solar battery unit. FIG. 23is a partially enlarged view enlarging and showing a part near a secondelectrode connecting portion 164, and FIG. 24 is a schematiccross-sectional view taken along a line XXIV—XXIV in FIG. 23. FIG. 25 isa schematic plan view enlarging and showing the central portion of thesolar battery unit shown in FIG. 22. FIG. 26A, FIG. 26B and FIG. 26C areschematic plan views separately showing the second electrode, thesemiconductor layer and the first electrode of the solar battery unitshown in FIG. 25, respectively. FIG. 27 is a plan view similar to FIG.25, showing another form example of the power generation portions at thecentral portion of the solar battery unit. FIG. 28 is a cross-sectionalview enlarging and showing a part of the liquid crystal display deviceconstituted of the liquid crystal display panel 90 and the solar batteryunit 120 shown in FIG. 21.

In the liquid crystal display panel 90, as shown in FIG. 21 and FIG. 28,first and second transparent substrates 21 and 22 are bonded togetherwith a predetermined gap interposed therebetween with spacers (notshown) and a sealing portion 115, and a liquid crystal layer 114 isfilled into the gap and sealed with a closing material (not shown).Through holes, into which the hand shaft 141 is inserted, are formedrespectively at centers of the first substrate 21 and the secondsubstrate 22, and the peripheries thereof are also sealed with thesealing portion 115.

A large number of signal electrodes 101 each made of a transparentconductive film are formed in stripes in a direction parallel to thepaper surface on the inner surface of the second substrate 22. On theinner surface of the first substrate 21 opposed to the aforesaid innersurface of the second substrate 22 with the predetermined gap interposedtherebetween, a large number of opposed electrodes 104 each made of atransparent conductive film are formed in stripes in a directionperpendicular to the paper surface. Portions where the signal electrodes101 intersect and overlap the opposed electrodes 104 form pixelportions.

For the liquid crystal layer 114, a mixed liquid crystal layer is used,which contains a transparent solid substance made by injecting a host inwhich organic monomers are dispersed in a liquid crystal and thereafterapplying ultraviolet light thereto to thereby polymerize them intoorganic polymers. As the liquid crystal layer 114, PNM-157 manufacturedby Dainippon Ink and Chemicals, Inc. is used and filled in anenvironment at a temperature of 20° C. or more, and thereafterultraviolet light of 365 nanometers (nm) is applied thereto at astrength of 30 mW for 60 seconds in an atmosphere at 19.5° C., therebyproducing the mixed liquid crystal layer composed of the liquid crystaland the transparent solid substance.

The mixed liquid crystal layer 114 is in a scattering state when novoltage is applied to the pixel portions because of a great differencein refractive index between the liquid crystal and the transparent solidsubstance, and is brought into a transparent state because thedifference in refractive index between the liquid crystal and thetransparent solid substance decreases by applying voltage.

Under the second substrate 22, a reflector 121 is disposed, which ismade by forming an anodic oxide film on an aluminum substrate andfurther forming a transparent protection film by evaporating an aluminum(Al) film. This reflector 121 does not transmit light, giving priorityto reflectance. Further, a through hole into which the hand shaft 141 isinserted is also formed at the center of the reflector 121 as shown inFIG. 21.

Next, the structure of the solar battery unit 120 is explained withreference to FIG. 22 to FIG. 28.

In the solar battery unit 120, as clearly shown in FIG. 22 to FIG. 24,first electrodes (lower electrodes) 167 each made of an indium tin oxide(ITO) film which is a transparent conductive film are formed on a solarbattery substrate 160 made of a glass substrate, power generatingsemiconductor layers 168 each having a PIN junction or a PN junction andmade of an amorphous silicon (a-Si) film, and buffer layers 170 (seeFIG. 24) for preventing mutual diffusion are provided to overlap thefirst electrodes 167, and further, second electrodes (upper electrodes)169 each made of an indium tin oxide (ITO) film are provided to overlapthe buffer layers 170, thereby constituting the power generationportions in vertical stripes.

A large number of the power generation portions 138 are formed parallelto each other with spaced intervals therebetween as shown in FIG. 22 andFIG. 23. Portions where no power generation portions 138 are provided onthe solar battery substrate 160 are transmission portions 139 fortransmitting light. This results in that the power generation portions138 and the transmission portions 139 are alternately provided.

As shown in FIG. 24, widths of the second electrode 169, the bufferlayer 170 and the power generating semiconductor layer 168 in the powergeneration portion 138 are the same as that of a width W1 of the powergeneration portion 138 and are made considerably smaller than a width W2of the transmission portion 139 between the power generation portions138. The widths of the power generation portion 138 and the transmissionportion 139 are not so different in FIG. 23 to FIG. 28 for convenienceof illustration, but the width W2 of the transmission portion 139 isactually far larger than the width W1 of the power generation portion138.

For example, the width W1 of the power generation portion 138 is made 20micrometers (μm), and the width W2 of the transmission portion 139 ismade 180 micrometers (μm). This brings an area proportion occupied bythe power generation portions 138 (proportion of the power generationportions) on the solar battery substrate 160 to about 10%.

The watch requires low power consumption, and thus even the areaproportion occupied by the power generation portions 138 of about 10%enables effective power generation.

Further, as shown in FIG. 24 and FIG. 28, a protection layer 175 made ofa polyimide resin is provided over the entire surface to preventdeterioration of the power generation portions 138 due to humidity.

The protection layer 175 is disposed on the first substrate 21 side ofthe liquid crystal display panel 90, and the solar battery substrate 160is disposed on the visual recognition side as shown in FIG. 28 in anactual watch.

An ultraviolet light cut layer 135 made of an acrylic resin adhesivelayer containing titanium oxide (TiO) as an ultraviolet light reflectingmaterial and a polyethylene terephthalate (PET) film is provided on thevisual recognition side (upper side) of the solar battery unit 120. Thisultraviolet light cut layer 135 has a transmittance of 1% to 3% within ashort wavelength region less than 380 nanometers (nm) and atransmittance of 50% at a wavelength of 400 nanometers (nm), and atransmittance of about 90% at a wavelength longer than 420 nanometers(nm).

The solar battery unit 120 constituted by the above-describedstructures, the liquid crystal display panel 90 and the like constitutethe liquid crystal display device having the function of generatingelectric power, in which the ultraviolet light cut layer 135, the solarbattery unit 120, the first substrate 21 and the second substrate 22 ofthe liquid crystal display panel 90, and the reflector 121 are arranged,from the upper side near a cover glass 102, in a watch case 100 as shownin FIG. 21. Further, any of them is formed with a through hole throughwhich the hand shaft 141, protruding from a hand shaft drive portion 131disposed under the reflector 121 and vertically extending, passes.

A minute hand shaft and an hour hand shaft are coaxial on the hand shaft141 which is inserted into the above-described through holes to protrudeinto a space between the cover glass 102 and the solar battery unit 120.The minute hand 142 and the hour hand 143 (see FIG. 20) are joined tothe tip portions of the minute hand shaft and the hour hand shaftrespectively. A second hand shaft may be provided in the center of thehand shaft 141 so that a second hand may be joined to the tip portionthereof.

A circuit board 132 is disposed under the hand shaft drive portion 131.The circuit board 132 is formed with circuits for applying predeterminedsignals to the liquid crystal display panel 90, the hand shaft driveportion 131 and an upper auxiliary light source 147 described below, andfurther, a secondary battery 133 for accumulating generated energy fromthe solar battery unit 120 is mounted thereon.

Further, the upper auxiliary light source 147 composed of anelectro-luminescent (EL) element is provided at the outer peripheralportion between the solar battery unit 120 and the liquid crystaldisplay panel 90 inside this watch. This electro-luminescent (EL)element has a light emitting surface on the first substrate 21 side ofthe liquid crystal display panel 90, thus forming a structure in whichthe polyethylene terephthalate (PET) film, a front surface electrodemade of a transparent conductive film, a light emitting layer, adielectric layer and a rear surface electrode made of carbon arelaminated in order from the first substrate 21 side.

The emitted light from the upper auxiliary light source 147 passesthrough the first substrate 21 and is repeatedly reflected and refractedby the liquid crystal layer 114 having a scattering property and thereflector 121, and further guided toward the center (the through hole145) of the liquid crystal display panel 90 by reflection of the secondelectrode 169 of the solar battery unit 120.

The structure of protecting the through hole 145 in the solar batteryunit 120 and connecting means of the large number of power generationportions 138 are explained here.

As shown in FIG. 22, the solar battery unit 120 has the through hole 145at the center of the solar battery substrate 160, and a resin portion146 having a resin portion hole 148 is provided at the through hole 145to prevent breakage of the solar battery substrate 160. Further, a notchportion 156 for positioning is provided at the top of the solar batterysubstrate 160.

A second electrode connecting portion 162 in an arc shape is provided atthe upper end in FIG. 22 of the number of the power generation portions138 in vertical stripes, and a second electrode pad portion 161 isprovided at one end thereof. Further, a first electrode connectingportion 164 in an arc shape is provided at the lower end of the powergeneration portions 138, and a first electrode pad portion 163 isprovided at one end thereof.

In the power generation portions 138, first electrodes 167 extendlongest at the lower ends as shown in FIG. 23, and all of them areconnected with the first electrode connecting portion 164 and connectedto the first electrode pad portion 163.

Although the upper ends of the power generation portions 138 are notshown, second electrodes 169 extend longest, and all of them areconnected with the second electrode connecting portion 162 and connectedto the second electrode pad portion 161.

However, at the portion where the through hole 145 is provided in thesolar battery substrate 160, since the power generation portion 138 isparted, the first electrode 167 is connected to an adjacent firstelectrode 167 through first electrode detouring portions 171 as shown inFIG. 25 and FIG. 26A to FIG. 26C. Further, the power generatingsemiconductor layer 168 is provided with projecting portions 176projecting into the first electrode detouring portions 171 to prevent anelectrical short circuit between the first electrode 167 and the secondelectrode 169.

On the other hand, the second electrode 169 is connected to an adjacentsecond electrode 169 through second electrode detouring portions 172.The projecting portions 176 of the power generating semiconductor layer168 also projecting into the second electrode detouring portions 172.

As described above, the first electrode 167 and the second electrode 169near the through hole 145 are mutually connected with the adjacent firstelectrode 167 and the adjacent second electrode 169 through thedetouring portions 171 and 172 respectively.

FIG. 26C shows the through hole 145 formed near the center on the solarbattery substrate 160 and the resin portion 146 which is formed at thethrough hole 145, and a state in which the first electrodes and thefirst electrode detouring portions 171 constituting the power generationportions 138 are formed. The power generating semiconductor layers 168having the projecting portions 176 shown in FIG. 26B are formedoverlapped on the first electrodes 167 shown in FIG. 26C. Further, thesecond electrodes having the second electrode detouring portions 172shown in FIG. 26A are formed overlapped on the power generatingsemiconductor layers 168.

FIG. 27 is a view showing another structural example for the powergeneration portions 138 to detour the through hole 145 and the resinportion 146 of the solar battery substrate 160. It is also possible thatportions of the power generation portions 138 near the center whichinterfere with the resin portion 146 are made thinner in width and arebent outward to an extent at which they do not touch the adjacent powergeneration portions, thereby forming detouring portions 173 which detourthe resin portion 146 as in the drawing. The power generation portions138 are thus provided also at the central portion where the through hole145 exists, so that the first electrode 167 and the second electrode 169can be connected to other identical electrodes respectively.

Further, the first electrode pad portion 163 and the second electrodepad portion 161 shown in FIG. 22 provided at the solar battery unit 120are connected to the circuit board 132 through a solar battery unitconnecting portion 158 and a connecting unit 159 composed of a flexibleprint circuit board (FPC) shown in FIG. 21. The connection isestablished by crimp using anisotropic conductive paste in thisembodiment.

As shown in the same FIG. 21, the front surface electrode and the rearsurface electrode of the upper auxiliary light source 147 are alsoelectrically connected using the same connecting unit 159 composed ofFPC and an upper auxiliary light source connecting portion 157. Theelectrode pad portions 161 and 163 of the solar battery unit 120 and theelectrodes of the upper auxiliary light source 147 are located to faceeach other, so that a press of the solar battery unit 120 and the upperauxiliary light source 147 against each other establishes an electricconnection thereof to the connecting unit 159. Further, the use of thesame FPC facilitates the connection to the circuit board 132.

Further, a panel holder 126 is provided to hold the liquid crystaldisplay panel 90, and zebra rubber connectors 127, in which conductiveportions and insulating portions are laminated in stripes, connects theliquid crystal display panel 90 and the circuit board 132. Thus, itbecomes possible to mount a timepiece module constituted of the liquidcrystal display panel 120, the hand shaft drive portion 131, the circuitboard 132 and the like.

Further, a panel cover 125 is provided at the back side of the coverglass 102 in order to shield the panel holder 126 of the timepiecemodule and to improve visual design.

This timepiece module is inserted into the watch case 100, the coverglass 102 and a case back 103, thereby completing a wristwatch.

The directions of light when an external light source (not shown) andthe upper auxiliary light source 147 are in use are explained here withFIG. 28. A first incident light c from the external light source is madeincident on the power generation portion 138 and used for optical powergeneration. A second incident light a is brought into a reflected lightb by the reflector 121 and goes out to the visual recognition side whilethe liquid crystal layer 114 is in a transmission state, therebyallowing an observer to recognize the state of the reflector 121.

While the liquid crystal layer 114 is in a scattering state, the secondincident light a does not show the mirror state of the reflector 121 butis brought into a scattering light. In other words, a contrast ratio isobtained by a mirror property in the transmission state and a scatteringproperty in the scattering state. Accordingly, the quantity of lightreaching the visual recognition side is large even in the scatteringstate, thereby achieving a bright display.

Alternatively, while the liquid crystal layer 114 is in the scatteringstate, the scattering light is made incident on the power generationportion 138 of the solar battery unit 120 from the side wall sidethereof, increasing the quantity of power generation.

On the other hand, an incident light d from the upper auxiliary lightsource 147 when the upper auxiliary light source 147 is turned onbecomes a component on the solar battery substrate 160 side as a firstscattering light e and a second outgoing light j, and a component on thereflector 121 side as a third scattering light g. The first scatteringlight e is reflected by the second electrode 169 of the power generationportion 138 on the solar battery substrate 160 and is made incidentagain on the liquid crystal layer 114 as a second scattering light f.

The second outgoing light j goes out to the visual recognition sidethrough the transmission portion 139 of the solar battery substrate 160.The third scattering light g is reflected by the reflector 121 to becomea fourth scattering light h, and is scattered by the liquid crystallayer 114 to become a first outgoing light i, a fifth scattering light kand a sixth scattering light m.

The reflection by the power generation portion 138, the reflection bythe reflector 121 and the transmission and scattering by the liquidcrystal layer 114 are similarly repeated, the emitted light from theupper auxiliary light source 147 which is provided around the displayregion of the liquid crystal display panel 90 is guided into the displayregion. Further, the outgoing light can present information to theobserver.

According to this embodiment, the provision of the ultraviolet light cutlayer 135 on the upper side of the solar battery unit 120 can preventexcessive energy from being made incident on the power generationportion 138 and additionally light with a short wavelength (ultravioletlight) having a high energy from being made incident on the liquidcrystal layer 114 of the liquid crystal display panel 90.

The watch including this solar battery unit can be used for a long timewithout replacement of batteries, realizing a maintenance-free watch.

Further, the solar battery unit 120 and the upper auxiliary light source147 are connected to the circuit board 132, with their electrodesarranged facing each other, using the same FPC (connecting unit) 159,thereby both stabilizing their connection and reducing the connectionspace by crimping and holding by means of the panel holder 126.

Further, the provision of the upper auxiliary light source 147 betweenthe solar battery unit 120 and the first substrate 21 of the liquidcrystal display panel 90, and further the use of the mixed liquidcrystal layer composed of the liquid crystal and the transparent solidsubstance for the liquid crystal layer 114, and the provision of thereflector 121 under the liquid crystal display panel 90 can guide theemitted light from the upper auxiliary light source 147 to the centralportion of the display region of the liquid crystal display panel 90.

The provision of the resin portion 146 at the through hole 145 providedin the solar battery unit 120 and the periphery thereof can preventdistortion and breakage of the solar battery substrate 160 due to thethrough hole 145. Further, the resin portion 146 can prevent breakage ofthe solar battery unit 120 when an impact exerted on the watch.

The width of the power generation portion 138 provided in the solarbattery unit 120 is made small as compared to the transmission portion139, thereby making it possible to clearly recognize the display on theliquid crystal display panel 90 through the transmission portion 139.

Furthermore, the second electrode 169 and the first electrode 167 of thepower generation portion 138 of the solar battery unit 120 are both madeof transparent conductive films, thereby improving the transmissionproperty and increasing the power generation efficiency using diffusingreflection from the liquid crystal display panel 90.

In the solar battery unit 120 as shown in FIG. 27, it is also possiblethat the power generating semiconductor layer 168 of the powergeneration portion 138 is a semiconductor layer including a PIN junctionor a PN junction made of a amorphous silicon (a-Si) film, on which analuminum (Al) film which is a metal film having a reflection property isformed as the second electrode 169 through a buffer for preventingmutual diffusion.

For easy recognition of the arrangement of the lower electrode 167, thesemiconductor layer 168 and the second electrode 169, the semiconductorlayer 168 is wider than the first electrode 167, and the secondelectrode 169 is narrower than the first electrode 167 in widthdimension in FIG. 27, but they may actually have the same width. Forexample, the width of the power generation portion 138 is made 10micrometers (μm), and the width of the transmission portion 139 is made50 micrometers (μm), thereby bringing the proportion of an area occupiedby the power generation portions 138 (the proportion of the powergeneration portions) on the solar battery substrate 160 to about 20%.

Further, when the through hole 145 is sufficiently larger than thepitches of the stripes of the power generation portions 138 and thetransmission portions 139, the detouring portions 173 can be provided ina plurality of the power generation portions 138 around the through hole145 to detour the through hole 145 with the pitches made smaller,thereby making the power generation portions 138 in pseudo stripes. Whenthe width of the transmission portion 139 is not enough for theformation of the detouring portions 173, it is preferable to provide thedetouring portions 173 in a plurality of the power generation portions138 on either side of the through hole 145.

Third Embodiment of Timepiece: FIG. 29

Next, the third embodiment of the timepiece according to the presentinvention is explained with FIG. 29.

FIG. 29 is a cross-sectional view, similar to FIG. 21, showing the thirdembodiment of the timepiece according to the present invention, in whichthe same numerals are given to portions corresponding to those in FIG.21 and the description thereof is omitted.

The third embodiment is characterized in that an ultraviolet light cutlayer 135 and a light wavelength conversion layer 134 are provided onthe visual recognition side of a solar battery unit 120 and an upperauxiliary light source 147 is provided above the ultraviolet light cutlayer 135. Further, each timepiece of embodiments after the thirdembodiment is a timepiece by a digital display by means of a liquidcrystal display panel.

In the third embodiment, the width of the power generation portion ofthe solar battery unit 120 is made 50 micrometers (μm), and the width ofthe transmission portion is made 100 micrometers (μm), whereby theproportion of an area occupied by the power generation portions (theproportion of the power generation portions) on the solar batterysubstrate is made about 30%. The power generation efficiency of thepower generation portion is poor because a plastic substrate is used forthe solar battery substrate, and thus the proportion is made about 30%.

An ultraviolet light cut layer 135 which absorbs light with a wavelengthof 300 nanometers (nm) to 400 nanometers (nm), constituted of apolyethylene terephthalate (PET) film absorbing light with a wavelengthshorter than a range of 300 nanometers (nm) to 320 nanometers (nm) andan adhesive layer, is provided on the visual recognition side (upperside in the drawing) of the solar battery unit 120.

Further, the light wavelength conversion layer 134 which emits lightwith a wavelength ranging from 400 nanometers (nm) to 800 nanometers(nm) when making a transition into a ground state after an energy statebeing excited by light with a wavelength of 300 nanometers (nm) to 380nanometers (nm), is provided on the ultraviolet light cut layer 135. Thelight wavelength conversion layer 134 contains a rare earth oxide in aglass material.

The emission is of a specific wavelength range within a wavelength rangeof 400 nanometers (nm) to 800 nanometers (nm). For example, ultravioletlight is absorbed and green light or red light is emitted.

The light wavelength conversion layer 134 can convert light with a shortwavelength (ultraviolet light) which deteriorates a power generationlayer of the solar battery unit 120 to light with a wavelength effectivein power generation of the solar battery unit 120.

Further, the light with a short wavelength can be blocked by theultraviolet light cut layer 135, thereby preventing deterioration of thesolar battery unit 120 and deterioration of a liquid crystal layer 114,and further preventing deterioration of the plastic substrateconstituting the solar battery unit 120 or deterioration of a resinwhich bonds a first substrate 21 of a liquid crystal display panel 90and the solar battery unit 120.

The solar battery unit 120 is connected to a circuit board 132 by meansof a connecting unit 159 composed of an FPC through a solar battery unitconnecting portion 158. A terminal of the FPC is inserted between thesolar battery unit 120 and the first substrate 21 of the liquid crystaldisplay panel 90, and reinforced with an adhesive containing diffusedconductive particles, a resin bonding the solar battery unit 120 and thefirst substrate 21 and further with the ultraviolet light cut layer 135and the light wavelength conversion layer 134, thereby enabling tosecure an electric connection.

Furthermore, an upper auxiliary light source 147 composed of anelectro-luminescent (EL) element is provided at the outer peripheralportion on the upper side of the light wavelength conversion layer 134.Since the upper auxiliary light source 147 is provided with its lightemitting surface directed to the liquid crystal display panel 90 side,its electrodes exist at its upper side, enabling an electric connectionof the terminal of the connecting unit 159 composed of the FPC theretowith the adhesive containing diffused conductive particles and bypressing by a panel holder 126.

As is clear from the above explanation, the provision of the ultravioletlight cut layer 135 on the upper side of the solar battery unit 120 canprevent excessive energy from being made incident on the powergeneration portion and light with a short wavelength (ultraviolet light)having a high energy from being made incident on the liquid crystallayer 114 of the liquid crystal display panel 90.

The conversion of light with a wavelength which adversely affects thesolar battery unit to light with a wavelength contributing to powergeneration by means of the light wavelength conversion layer 134 canimprove the power generation efficiency of the solar battery unit 120.

Moreover, ultraviolet light of the upper auxiliary light source 147 canbe converted in wavelength and applied to the liquid crystal displaypanel as visible light. Furthermore, the light of the upper auxiliarylight source 147 can be converted in wavelength and guided.

When a plastic substrate is used as the substrate of the solar batteryunit 120, the solar battery substrate can be held by the ultravioletlight cut layer 135, the light wavelength conversion layer 134 and thefirst substrate 21 of the liquid crystal display panel 90, therebypreventing distortion and the like of the solar battery unit 120.

The widths of the power generation portions constituting the solarbattery unit are made smaller than those of the transmission portions,and the widths of the power generation portions are made smaller than100 micrometers (μm), thereby decreasing recognition of the powergeneration portions and avoiding interference with recognition of thedisplay on the liquid crystal display panel through the transmissionportions of the solar battery unit.

Fourth Embodiment of Timepiece: FIG. 30

Next, the fourth embodiment of the timepiece according to the presentinvention is explained with FIG. 30.

FIG. 30 is a cross-sectional view similar to FIG. 21, showing only aninner module of the fourth embodiment of the timepiece according to thepresent invention, in which the same numerals are given to componentscorresponding to those in FIG. 21 and FIG. 29, and the descriptionthereof is omitted.

The fourth embodiment is characterized in that only a light wavelengthconversion layer 134 is provided on the upper side of a solar batteryunit 120, and that a zebra rubber connector 166 is used for a connectionbetween the solar battery unit 120 and a circuit board 132 similarly toa connection between a liquid crystal display panel 90 and the circuitboard 132.

Further, a reflection-type polarizing film 110, of which one polarizingoptical axis is a transmission axis and a polarizing optical axissubstantially perpendicular thereto is a reflection axis, is bonded tothe lower side of a second substrate 22 of the liquid crystal displaypanel 90 with an acrylic adhesive.

The reflection-type polarizing film 110 has a laminated structureconstituted of several-hundred layers of polymers and co-polymers, inwhich a difference in refractive index is generated in an axis byuniaxially stretching them, and the difference in the refractive indexdepending on wavelength generates polarization in transmission andreflection. Alternatively, a multi-layer structure composed of liquidcrystal and polymer can be employed. A polarizing film with a trade nameof DBEF (manufactured by Sumitomo 3M Ltd.) is used in this embodiment.

A lower auxiliary light source 119 is provided below the reflection-typepolarizing film 110. As the lower auxiliary light source 119, anelectro-luminescent (EL) element is employed when importance is attachedto a thin profile. Other than that, a light emitting diode (LED) device,a miniature bulb, a fluorescent tube can be used therefor.

Further, the solar battery unit 120 and the light wavelength conversionlayer 134 are provided above the first substrate 21 of the liquidcrystal display panel 90. Electric connection between the liquid crystaldisplay panel 90 and the circuit board 132 is established through zebrarubber connectors 127 in which conductive portions and insulatingportions are laminated in stripes.

The zebra rubber connector 166 is used for the connection between thesolar battery unit 120 and the circuit board 132. The zebra rubberconnector 166 for the solar battery unit is longer than the zebra rubberconnectors 127 for the liquid crystal display panel and connects withthe solar battery unit 120 passing by a side wall of the first substrate21.

In the timepiece of this embodiment, the provision of the lightwavelength conversion layer 134 on the upper side of the solar batteryunit 120 makes it possible to absorb excessive ultraviolet light andconvert it to light with a wavelength contributing to power generation,thereby improving the power generation efficiency of the solar batteryunit 120.

Further, the electric connection between the liquid crystal displaypanel 90 and the circuit board 132 and the electric connection betweenthe solar battery unit 120 and the circuit board 132 are establishedthrough the use of the zebra rubber connectors, made of the samematerial, thereby unifying the materials and uniforming the connections.

Furthermore, a zebra rubber connector is used for an electric connectionbetween the lower auxiliary light source 119 and the circuit board 132,making it possible to establish all the connections through the zebrarubber connectors.

Fifth Embodiment of Timepiece: FIG. 31

Next, the fifth embodiment of the timepiece according to the presentinvention is explained with FIG. 31.

FIG. 31 is a cross-sectional view similar to FIG. 30, showing only aninner module of the fifth embodiment of the timepiece according to thepresent invention, in which the same numerals are given to componentscorresponding to those in FIG. 21 and FIG. 29, and thus the descriptionthereof is omitted.

The fifth embodiment is characterized in that an ultraviolet light cutlayer 135 and a light wavelength conversion layer 134 are provided onthe upper side of a solar battery unit 120, and that a zebra rubberconnector is used for a connection between the solar battery unit 120and a circuit board 132 similarly to a connection between a liquidcrystal display panel 90 and the circuit board 132.

As in the above-described fourth embodiment, a reflection-typepolarizing film 110, of which one polarizing optical axis is atransmission axis and a polarizing optical axis substantiallyperpendicular thereto is a reflection axis, is bonded to the lower sideof a second substrate 22 of the liquid crystal display panel 90 with anacrylic adhesive. The reflection-type polarizing film 110 has alaminated structure constituted of several-hundred layers of polymersand co-polymers, in which a difference in refractive index is generatedin an axis by uniaxially stretching them, and the difference in therefractive index depending on wavelength generates polarization intransmission and reflection.

A lower auxiliary light source 119 is provided below the reflection-typepolarizing film 110. As the lower auxiliary light source 119, anelectro-luminescent (EL) element is employed when importance is attachedto a thin profile.

A predetermined gap is provided between the reflection-type polarizingfilm 110 and the second substrate 22, and the reflection-type polarizingfilm 110 is fixed to the lower auxiliary light source 119 with anadhesive (not shown). The provision of an air layer between thereflection-type polarizing film 110 and the second substrate 22apparently improves a scattering property of the liquid crystal displaypanel because of a difference in refractive index between the secondsubstrate 22, the air layer and the reflection-type polarizing film 110,which is effective.

When a color display is performed, it is effective to provide atransparent printed layer between the reflection-type polarizing film110 and the second substrate 22.

The solar battery unit 120, the ultraviolet light cut layer 135 and thelight wavelength conversion layer 134 are provided above a firstsubstrate 21, thereby effectively using ultraviolet light for powergeneration and preventing light having excessive energy from enteringthe solar battery unit 120 and a liquid crystal layer 114.

Sixth Embodiment of Timepiece: FIG. 32

Next, the sixth embodiment of the timepiece according to the presentinvention is explained with FIG. 32.

FIG. 32 is a cross-sectional view similar to FIG. 30, showing only aninner module of the sixth embodiment of the timepiece according to thepresent invention, in which the same numerals are given to componentscorresponding to those in FIG. 21 and FIG. 29, and the descriptionthereof is omitted.

The sixth embodiment is characterized in that an ultraviolet light cutlayer 135 is bonded to the upper side of a first substrate 21 of aliquid crystal display panel 90, and, with a predetermined gap, a solarbattery unit 120 and a light wavelength conversion layer 134 areprovided, and that an upper auxiliary light source 147 is provided onthe upper side of the light wavelength conversion layer 134.

The ultraviolet light cut layer 135 is provided on the upper side of thefirst substrate 21 of the liquid crystal display panel 90. Theultraviolet light cut layer 135 has a transmittance of about 1% withrespect to light with a wavelength shorter than 380 nanometers (nm),transmits 50% of light with a wavelength of 400 nanometers (nm), andtransmits about 90% of light with a wavelength of 420 nanometers (nm).

Above the ultraviolet light cut layer 135, the solar battery unit 120 isprovided with the predetermined gap interposed therebetween.

Further, the light wavelength conversion layer 134 which emits lightranging from 400 nanometers (nm) to 800 nanometers (nm) when making atransition into a ground state after an energy state being excited bylight with a wavelength of 300 nanometers (nm) to 380 nanometers (nm),is provided on the solar battery unit 120. The light wavelengthconversion layer 134 contains a rare earth oxide in a glass material.The emission is of a specific wavelength range within a wavelength rangeof 400 nanometers (nm) to 800 nanometers (nm). For example, ultravioletlight is absorbed and green light or red light is emitted.

The light wavelength conversion layer 134 can convert light whichdeteriorates a power generation layer of the solar battery unit 120 tolight effective in power generation of the solar battery unit 120 inwavelength.

Further, the light with a short wavelength can be blocked by theultraviolet light cut layer 135. These can prevent deterioration of thesolar battery unit 120 and deterioration of a liquid crystal layer 114,and further prevent deterioration of a plastic substrate constitutingthe solar battery unit 120 and deterioration of a resin which bonds thefirst substrate 21 and the solar battery unit 120.

Furthermore, the provision of the gap between the ultraviolet light cutlayer 135 and the solar battery unit 120 can prevent dust which appearsbetween the ultraviolet light cut layer 135 and the solar battery unit120 and breakage of the solar battery unit 120 which occurs in repairingthe ultraviolet light cut layer 135 caused by distortion of theultraviolet light cut layer 135 as compared to the case in which theultraviolet light cut layer 135 is bonded to the solar battery unit 120.

Other Structural Examples of Liquid Crystal Display Device: FIG. 33 andFIG. 34

Next, other structural examples of the liquid crystal display deviceused in the timepiece according to the present invention are explained.

FIG. 33 is an enlarged plan view of a pixel portion and its surroundingsof the liquid crystal display device.

This liquid crystal display device is characterized in that a solarbattery unit and a liquid crystal display panel having thin film diodes(TFD) as two-terminal active elements are provided on the samesubstrate.

In this liquid crystal display device, as shown in FIG. 33, dataelectrodes 47 each made of a tantalum (Ta) film are formed in verticalstripes on the inner surface (surface on the liquid crystal layer side)of a second transparent substrate 22 which is an active substrate of theliquid crystal display panel, and a display electrode 68 made of anindium oxide (ITO) film is formed between adjacent data electrodes 47and 47.

Further, a lower electrode 110 is extended from each data electrode 47for each display electrode 68, and a tantalum oxide (Ta₂O₅) film (notshown) made by anodizing a tantalum film is formed on the front face ofthe lower electrode 110 as a nonlinear resistance layer.

Further, an upper electrode 111 is extended from each display electrode68 to intersect and overlap the lower electrode 110 through thenonlinear resistance layer. The lower electrode 110, the nonlinearresistance layer and the upper electrode 111 constitute a thin filmdiode 112.

Since a predetermined voltage is applied to the data electrode 47 toapply a voltage between the display electrode 68 and an opposedelectrode, which is formed on the inner surface of a first substrate,opposed to the display electrode 68 with a not shown liquid crystallayer interposed therebetween to thereby perform a display, the liquidcrystal layer around the display electrode 68 is not caused to change bysignal, and thus an effective display can not be performed there.

Therefore, the solar battery unit is provided around the displayelectrodes 68. More specifically, a transparent insulating film isformed on the entire upper surface of the second substrate 22 which isformed with the data electrodes 47, the display electrodes 68 and thethin film diodes 112.

Then, first electrodes 167 are formed in horizontal stripes close to thedisplay electrodes 68 on the insulating film, power generatingsemiconductor layers 168 each made of an amorphous silicon (a-Si) filmare also formed in horizontal stripes overlapped on the first electrodes167. Further, second electrodes 169 are formed in a lattice shapeoverlapped on the power generating semiconductor layers 168 and abovethe data electrodes 47 to constitute power generation layers 138 wherethe first electrodes 167, the semiconductor layers 168 and the secondelectrodes 169 overlap one upon another.

As described above, the power generation portions 138 of the solarbattery unit are arranged around the display electrodes 68. Further,since a transparent conductive film is used for the not shown opposedelectrode, the power generation portion 138 is disposed in a directionperpendicular to the data electrode 47, making it possible to supplypredetermined light energy to the solar battery unit without influenceexerted upon display performance.

In this solar battery unit, a region corresponding to the displayelectrode 68, provided with no power generation portion 138, is atransmission portion 139, enabling a bright display by the liquidcrystal display panel.

Further, the arrangement of the second electrodes 169 in a lattice shapeand the arrangement of the semiconductor layers 168 in stripes make itpossible that when an auxiliary light source is disposed below theliquid crystal display panel and turned on, light to an ineffectivedisplay region around the display electrodes 68 can be blocked, which isextremely effective in improvement of display quality and in the powergeneration efficiency of the solar battery unit.

FIG. 34 is an enlarged plan view of a pixel portion and its surroundingsshowing still another example of the liquid crystal display device usedin the timepiece according to the present invention.

In this liquid crystal display device, a power generation portion of asolar battery unit, a data electrode and a display electrode of a liquidcrystal display panel and a pair of thin film diodes (TFD) which aretwo-terminal active elements are provided in the same substrate.

In this liquid crystal display device, data electrodes 47 each made of atransparent conductive film are formed in vertical stripes on the innersurface (surface on the liquid crystal layer side) of a secondtransparent substrate 22 which is an active substrate of the liquidcrystal display panel, and a display electrode 68 made of an indium tinoxide (ITO) film which is a transparent conductive film is formedbetween adjacent data electrodes 47 and 47.

Further, a first lower electrode 95 is integrally provided extendingfrom each data electrode 47 for each display electrode 68. Furthermore,a second lower electrode 96 is integrally provided extending from thedisplay electrode 68 to be parallel to the first lower electrode 95. Afirst electrode 167 of a power generation portion 138 of the solarbattery unit is formed in a vertical stripe in a gap between the dataelectrode 47 and the display electrode 68.

The data electrodes 47, the first lower electrodes 95, the displayelectrodes 68, the second lower electrodes 96 and the first electrodes167 of the power generation portions 138 are simultaneouslypattern-formed directly on the second substrate 22 using the sametransparent conductive film.

Then, semiconductor layers 165, 166, 168 each made of an amorphoussilicon (a-Si) film and having a PIN junction are provided on the firstlower electrode 95, the second lower electrode 96 and the firstelectrode 167 constituting the power generation portion 138,respectively. All of these semiconductor layers are formed of theabove-described same semiconductor.

Thereafter, a first upper electrode 162 which connects the semiconductorlayer 165 and the second lower electrode 96 is provided, constituting afirst thin film diode 98 by the first lower electrode 95, thesemiconductor layer 165 and the first upper electrode 162.

Further, a second upper electrode 163 which connects the semiconductorlayer 166 and the data electrode 47 is provided, constituting a secondthin film diode 99 by the second lower electrode 96, the semiconductorlayer 166 and the second upper electrode 163.

Since the first thin film diode 98 and the second thin film diode 99 areconnected to each other in a ring-like shape, photoelectromotive forcegenerated by the thin film diodes 98 and 99 is consumed in the ring.This can decrease influence exerted upon display quality of the liquidcrystal display device.

A second electrode 169 is formed in a vertical stripe of a transparentconductive film on the semiconductor layer 168 which is formed on thefirst electrode 167 of the solar battery unit, thereby constituting thepower generation portion 138. The power generation portion 138 can beprovided on the data electrode 47, but such provision makes it difficultto take out electric power because the data electrode 47 is used fordriving the thin film diodes 98 and 99, and thus the data electrode 47and the power generation portion 138 are separately constituted.

When the thin film diode is connected to a scanning electrode(horizontal electrode), the power generation portion 138 of the solarbattery unit is preferably disposed parallel to the scanning electrode.

In order to apply a signal to the data electrode 47 and take outelectric power generated by the power generation portion 138, there is amethod of connecting them to wirings through a flexible print circuit(FPC) or a chip-on-glass (COG). Alternatively, it is possible to employa method that the data electrode 47 and the second electrode 169 are ledout to this side from the paper surface, and the data electrodes 47 areconnected to each other through a second electrode connecting portion(not shown) at a position closer to the outer form of a first substrate(not shown) from a portion where the data electrode 47 is connected toan external circuit, and connected through a first electrode connectingportion (not shown) at the back side of the paper surface.

Alternatively, a method is also effective that the power generationportion 138 is made larger in width than the data electrode 47 at aposition where a sealing agent exists, and a conductive paste is printedon each first electrode 167 or each second electrode 169 to connect to afirst electrode connecting portion or a second electrode connectingportion (not shown) which is provided on a second substrate opposed tothe fist substrate.

Further, a nonlinear resistance element and the power generation portion138 are provided on the same substrate, thus reducing a load on theconnection. Furthermore, the first electrode 167 and the secondelectrode 169 of the power generation portion 138 are each made of atransparent conductive film, thereby enabling power generation even ifthe power generation portion 138 is provided either on the upper side oron the lower side of the liquid crystal layer (not shown).

Especially, in the case of a liquid crystal layer mode in which theliquid crystal layer exhibits absorption, scattering or reflectioncharacteristics and light passing through the liquid crystal layer isdecreased by the liquid crystal layer, the second substrate providedwith the power generation portions 138 is disposed on the visualrecognition side, thereby making it possible to secure a large quantityof power generation.

Other Modifications

Even when the solar battery unit is disposed on the visual recognitionside of the liquid crystal display panel, it is also possible toconstitute the solar battery unit in a lattice shape as in the exampleshown in FIG. 11 and FIG. 12 and sandwich the power generatingsemiconductor layer made of an amorphous silicon (a-Si) film at theintersection portion of the first electrode in a horizontal stripe andthe second electrode in a vertical stripe, thereby forming the powergeneration portion.

Even in such a solar battery unit, the transmission portion can occupyan large area corresponding to the display electrode forming the pixelportion of the liquid crystal display panel, enabling a bright displayby the liquid crystal display panel and also enabling a performance of atransmission-type display by disposing an auxiliary light source belowthe liquid crystal display panel.

Although the example in which the two-terminal type thin film diode isprovided as the nonlinear resistance element (switching element)provided in the liquid crystal display panel is given, thethree-terminal type nonlinear resistance element typified by the thinfilm transistor (TFT) as shown in FIG. 15 may be provided.

INDUSTRIAL APPLICABILITY

A timepiece according to the present invention is equipped with a liquidcrystal display device having a function of generating electric power,in which a function of generating electric power by a solar battery canbe obtained in an area of a liquid crystal display panel, therebysecuring a sufficient area for a liquid crystal display even if theliquid crystal display device is installed in a small-sized timepieceand also making it possible to eliminate power supply from the outsideand battery exchange, thus solving the environmental problems andproblems on the supply of energy, with a realization of amaintenance-free timepiece. Moreover, the timepiece is excellent invisual design because the solar battery is not viewed from the outsideof the timepiece.

1. A liquid crystal display device, comprising: a liquid crystal displaypanel including a transmission portion; a solar battery facing at leasta part of a surface opposite to a visual recognition side of said liquidcrystal display panel and absorbing a visible light to generate electricpower; a first polarizing film provided on the visual recognition sideof said liquid crystal display panel, said first polarizing film havinga polarization transmission axis; and a second polarizing film providedon a side opposite the visual recognition side of said liquid crystalpanel, said second polarizing film having a polarization transmissionaxis substantially perpendicular to the polarization transmission axisof said first polarizing film, wherein light is applied to said solarbattery through the transmission portion of said liquid crystal displaypanel to generate electric power, and a display by said liquid crystaldisplay panel is performed using said solar battery as an absorbingplate, and wherein said liquid crystal display panel, said firstpolarizing film and said second polarizing film are in a transmissionstate where light is applied to the solar battery through said liquidcrystal display panel when a voltage applied to the liquid crystal panelis off.
 2. The liquid crystal display device according to claim 1,wherein a film having characteristics of transmitting light within awavelength region matching with wavelength absorbed by a powergeneration portion of said solar battery is provided on the visualrecognition side of said solar battery.
 3. The liquid crystal displaydevice according to claim 2, wherein a power generation quantityadjustment region for changing a transmittance is provided at a part ofa display region of said liquid crystal display panel to adjust aquantity of power generation of said solar battery.
 4. The liquidcrystal display device according to claim 3, wherein said liquid crystaldisplay panel is a liquid crystal display panel for a timepiece.
 5. Theliquid crystal display device according to claim 2, wherein means forconducting a control to increase a transmittance of said liquid crystaldisplay panel is provided to increase a quantity of power generation ofsaid solar battery while said liquid crystal display panel is in anon-driving display state.
 6. The liquid crystal display deviceaccording to claim 5, wherein said liquid crystal display panel is aliquid crystal display panel for a timepiece.
 7. The liquid crystaldisplay device according to claim 2, wherein a liquid crystal layer ofsaid liquid crystal display panel is a mixed liquid crystal layercontaining a polymer in a liquid crystal.
 8. The liquid crystal displaydevice according to claim 7, wherein said liquid crystal display panelis a liquid crystal display panel for a timepiece.
 9. The liquid crystaldisplay device according to claim 2, wherein a liquid crystal layer ofsaid liquid crystal display panel is a twisted nematic liquid crystallayer or a super twisted nematic liquid crystal layer, polarizing filmsare provided on the visual recognition side and on the opposite sidethereto respectively with said liquid crystal layer interposedtherebetween, and said polarizing film provided on the opposite side tothe visual recognition side is a reflection-type polarizing film ofwhich one polarization axis is a transmission axis and anotherpolarization axis substantially perpendicular thereto is a reflectionaxis.
 10. The liquid crystal display device according to claim 9,wherein said liquid crystal display panel is a liquid crystal displaypanel for a timepiece.
 11. The liquid crystal display device accordingto claim 2, wherein said liquid crystal display panel is a liquidcrystal display panel for a timepiece.
 12. The liquid crystal displaydevice according to claim 1, wherein a printed layer havingsubstantially same spectral reflectance as that of a power generationportion of said solar battery is provided on non-power-generationportions of said solar battery.
 13. The liquid crystal display deviceaccording to claim 12, wherein a power generation quantity adjustmentregion for changing a transmittance is provided at a part of a displayregion of said liquid crystal display panel to adjust a quantity ofpower generation of said solar battery.
 14. The liquid crystal displaydevice according to claim 13, wherein said liquid crystal display panelis a liquid crystal display panel for a timepiece.
 15. The liquidcrystal display device according to claim 12, wherein means forconducting a control to increase a transmittance of said liquid crystaldisplay panel is provided to increase a quantity of power generation ofsaid solar battery while said liquid crystal display panel is in anon-driving display state.
 16. The liquid crystal display deviceaccording to claim 15, wherein said liquid crystal display panel is aliquid crystal display panel for a timepiece.
 17. The liquid crystaldisplay device according to claim 12, wherein a liquid crystal layer ofsaid liquid crystal display panel is a mixed liquid crystal layercontaining a polymer in a liquid crystal.
 18. The liquid crystal displaydevice according to claim 17, wherein said liquid crystal display panelis a liquid crystal display panel for a timepiece.
 19. The liquidcrystal display device according to claim 12, wherein a liquid crystallayer of said liquid crystal display panel is a twisted nematic liquidcrystal layer or a super twisted nematic liquid crystal layer,polarizing films are provided on the visual recognition side and on theopposite side thereto respectively with said liquid crystal layerinterposed therebetween, and said polarizing film provided on theopposite side to the visual recognition side is a reflection-typepolarizing film of which one polarization axis is a transmission axisand another polarization axis substantially perpendicular thereto is areflection axis.
 20. The liquid crystal display device according toclaim 19, wherein said liquid crystal display panel is a liquid crystaldisplay panel for a timepiece.
 21. The liquid crystal display deviceaccording to claim 12, wherein said liquid crystal display panel is aliquid crystal display panel for a timepiece.
 22. The liquid crystaldisplay device according to claim 1, wherein a film for changing a colorof said solar battery is provided between said solar battery and saidliquid crystal display panel.
 23. The liquid crystal display deviceaccording to claim 22, wherein said film for changing a color of saidsolar battery is a cholesteric liquid crystal film.
 24. The liquidcrystal display device according to claim 23, wherein a liquid crystallayer of said liquid crystal display panel is a twisted nematic liquidcrystal layer or a super twisted nematic liquid crystal layer, and apolarizing film is provided on the visual recognition side and acholesteric liquid crystal film is provided on the opposite side theretorespectively with said liquid crystal layer interposed therebetween. 25.The liquid crystal display device according to claim 24, wherein saidliquid crystal display panel is a liquid crystal display panel for atimepiece.
 26. The liquid crystal display device according to claim 22,wherein a display is performed by a change in color of said liquidcrystal display panel and a spectral reflection characteristic of saidfilm.
 27. The liquid crystal display device according to claim 22,wherein said liquid crystal display panel is a liquid crystal displaypanel for a timepiece.
 28. The liquid crystal display device accordingto claim 1, wherein a power generation quantity adjustment region forchanging a transmittance is provided at a part of a display region ofsaid liquid crystal display panel to adjust a quantity of powergeneration of said solar battery.
 29. The liquid crystal display deviceaccording to claim 28, wherein said liquid crystal display panel is aliquid crystal display panel for a timepiece.
 30. The liquid crystaldisplay device according to claim 1, wherein means for conducting acontrol to increase a transmittance of said liquid crystal display panelis provided to increase a quantity of power generation of said solarbattery while said liquid crystal display panel is in a non-drivingdisplay state.
 31. The liquid crystal display device according to claim30, wherein said liquid crystal display panel is a liquid crystaldisplay panel for a timepiece.
 32. The liquid crystal display deviceaccording to claim 1, wherein a display is performed by a change incolor of said liquid crystal display panel and a spectral reflectioncharacteristic of said solar battery.
 33. The liquid crystal displaydevice according to claim 1, wherein a liquid crystal layer of saidliquid crystal display panel is a mixed liquid crystal layer made bymixing a dichroic dye in a liquid crystal.
 34. The liquid crystaldisplay device according to claim 33, wherein said liquid crystaldisplay panel is a liquid crystal display panel for a timepiece.
 35. Theliquid crystal display device according to claim 1, wherein a liquidcrystal layer of said liquid crystal display panel is a mixed liquidcrystal layer containing a polymer in a liquid crystal.
 36. The liquidcrystal display device according to claim 35, wherein said liquidcrystal display panel is a liquid crystal display panel for a timepiece.37. The liquid crystal display device according to claim 1, wherein aliquid crystal layer of said liquid crystal display panel is a twistednematic liquid crystal layer or a super twisted nematic liquid crystallayer, polarizing films are provided on the visual recognition side andon the opposite side thereto respectively with said liquid crystal layerinterposed therebetween, and said polarizing film provided on theopposite side to the visual recognition side is a reflection-typepolarizing film of which one polarization axis is a transmission axisand another polarization axis substantially perpendicular thereto is areflection axis.
 38. The liquid crystal display device according toclaim 37, wherein said liquid crystal display panel is a liquid crystaldisplay panel for a timepiece.
 39. The liquid crystal display deviceaccording to claim 1, wherein said liquid crystal display panel is aliquid crystal display panel for a timepiece.